U.S. patent number 9,506,633 [Application Number 14/301,859] was granted by the patent office on 2016-11-29 for sealed and sealable lighting systems incorporating flexible light sheets and related methods.
This patent grant is currently assigned to COOLEDGE LIGHTING INC.. The grantee listed for this patent is Paul Palfreyman, Michael A. Tischler. Invention is credited to Paul Palfreyman, Michael A. Tischler.
United States Patent |
9,506,633 |
Tischler , et al. |
November 29, 2016 |
Sealed and sealable lighting systems incorporating flexible light
sheets and related methods
Abstract
In accordance with certain embodiments, lighting systems include
flexible light sheets and one or more sealed regions containing
light-emitting elements, the sealed regions defined by seals
between a top housing and a bottom housing and/or the light
sheet.
Inventors: |
Tischler; Michael A.
(Vancouver, CA), Palfreyman; Paul (Vancouver,
CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Tischler; Michael A.
Palfreyman; Paul |
Vancouver
Vancouver |
N/A
N/A |
CA
CA |
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Assignee: |
COOLEDGE LIGHTING INC.
(Richmond, CA)
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Family
ID: |
52005330 |
Appl.
No.: |
14/301,859 |
Filed: |
June 11, 2014 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20140362566 A1 |
Dec 11, 2014 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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14195175 |
Mar 3, 2014 |
8884534 |
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13970027 |
Aug 19, 2013 |
8704448 |
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13799807 |
Mar 13, 2013 |
8947001 |
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61834183 |
Jun 12, 2013 |
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61697411 |
Sep 6, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F21V
19/005 (20130101); E04B 9/32 (20130101); F21V
7/00 (20130101); F21V 19/02 (20130101); F21V
33/006 (20130101); F21V 31/005 (20130101); F21V
23/06 (20130101); H05B 45/46 (20200101); F21V
31/00 (20130101); F21V 15/01 (20130101); F21V
23/001 (20130101); E04B 9/241 (20130101); F21S
8/026 (20130101); F21Y 2105/10 (20160801); F21V
5/007 (20130101); H05K 2201/2054 (20130101); F21V
17/101 (20130101); F21V 7/0083 (20130101); H05K
2201/10106 (20130101); F21Y 2115/10 (20160801); F21V
5/008 (20130101); H05K 3/284 (20130101) |
Current International
Class: |
H05B
33/08 (20060101); F21V 33/00 (20060101); F21V
21/35 (20060101); F21V 31/00 (20060101); E04B
9/32 (20060101); F21V 19/00 (20060101); F21V
15/01 (20060101); E04B 9/24 (20060101); F21V
21/14 (20060101); F21K 99/00 (20160101); F21V
17/10 (20060101); F21V 7/00 (20060101); F21V
5/00 (20150101); H05K 3/28 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2007-115550 |
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May 2007 |
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JP |
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2007-531321 |
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Nov 2007 |
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JP |
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2007-335866 |
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Dec 2007 |
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JP |
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2011-65829 |
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Mar 2011 |
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JP |
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2012-43756 |
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Mar 2012 |
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JP |
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10-2010-0129414 |
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Dec 2010 |
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KR |
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98/23896 |
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Jun 1998 |
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WO |
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2013/001528 |
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Jan 2013 |
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WO |
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2013/021311 |
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Feb 2013 |
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WO |
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2014/039298 |
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Mar 2014 |
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WO |
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2014/200846 |
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Dec 2014 |
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WO |
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2014/201112 |
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Dec 2014 |
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WO |
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2014/201250 |
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Dec 2014 |
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WO |
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Other References
PCT International Patent Application No. PCT/US2013/056567,
International Search Report and Written Opinion mailed Dec. 23,
2013, 10 pages. cited by applicant .
PCT International Patent Application No. PCT/US2014/041280,
International Search Report and Written Opinion mailed Oct. 22,
2014, 14 pages. cited by applicant .
PCT International Patent Application No. PCT/US2014/041903,
International Search Report and Written Opinion mailed Nov. 12,
2014, 22 pages. cited by applicant .
PCT International Patent Application No. PCT/US2014/042126,
International Search Report and Written Opinion mailed Oct. 27,
2014, 9 pages. cited by applicant.
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Primary Examiner: Hammond; Crystal L
Attorney, Agent or Firm: Morgan, Lewis & Bockius LLP
Parent Case Text
RELATED APPLICATIONS
This application claims the benefit of and priority to U.S.
Provisional Patent Application No. 61/834,183, filed Jun. 12, 2013,
the entire disclosure of which is hereby incorporated herein by
reference. This application is also a continuation-in-part of U.S.
patent application Ser. No. 14/195,175, filed on Mar. 3, 2014,
which is a continuation of U.S. patent application Ser. No.
13/970,027, filed Aug. 19, 2013, now issued as U.S. Pat. No.
8,704,448, which is a continuation-in-part of U.S. patent
application Ser. No. 13/799,807, filed Mar. 13, 2013, which claims
the benefit of and priority to U.S. Provisional Patent Application
No. 61/697,411, filed Sep. 6, 2012, the entire disclosure of each
of which is hereby incorporated herein by reference.
Claims
What is claimed is:
1. A lighting system comprising: a substantially planar flexible
substrate having a first surface and a second surface opposite the
first surface; first and second spaced-apart power conductors
disposed over the first surface of the substrate; a plurality of
light-emitting strings forming a two-dimensional array over the
first surface of the substrate, each light-emitting string (i)
comprising a plurality of interconnected light-emitting elements
spaced along the light-emitting string, (ii) having a first end
electrically coupled to the first power conductor, and (iii) having
a second end electrically coupled to the second power conductor,
wherein the power conductors supply power to each of the
light-emitting strings; a plurality of conductive traces disposed
over the first surface of the substrate and each (i) electrically
interconnecting two light-emitting elements, or (ii) electrically
connecting a light-emitting element to a power conductor; and a
polymeric top housing disposed over the first surface of the
substrate and sealed to the first surface of the substrate at a
contact point between the top housing and the first surface of the
substrate to form a sealed region between the top housing and the
substrate, the sealed region containing therewithin the plurality
of light-emitting strings, the plurality of conductive traces, at
least a portion of the first power conductor, and at least a
portion of the second power conductor, wherein the lighting system
is separable, via a cut spanning the first and second power
conductors and not crossing a light-emitting string, into two
individually operable partial lighting systems each comprising (i)
one or more light-emitting strings, (ii) portions of the first and
second power conductors configured to supply power to and thereby
illuminate the one or more light-emitting strings of the partial
lighting system, and (iii) a sealed region defined by a seal
between a portion of the top housing and the substrate.
2. The lighting system of claim 1, further comprising, extending
from within the sealed region to outside of the sealed region, one
or more conductive couplings for supplying power from an external
power source to the light-emitting strings.
3. The lighting system of claim 2, wherein each partial lighting
system comprises, extending from within the sealed region of the
partial lighting system to outside of the sealed region of the
partial lighting system, one or more of the conductive
couplings.
4. The lighting system of claim 2, wherein at least one conductive
coupling is a portion of at least one of the first or second power
conductors.
5. The lighting system of claim 2, wherein at least one conductive
coupling comprises a conductive element piercing through at least
one of the top housing or the substrate and making electrical
contact to at least one of the first or second power
conductors.
6. The lighting system of claim 2, wherein at least one conductive
coupling comprises an electrical connector terminating outside of
the sealed region and configured to receive a complementary
connector or wire electrically connected to the external power
source.
7. The lighting system of claim 2, wherein at least one conductive
coupling is configured to convey a communication or control signal
to or from the light sheet.
8. The lighting system of claim 2, further comprising, extending
from within the sealed region to outside of the sealed region, one
or more second conductive couplings configured to convey a
communication or control signal to or from the light sheet.
9. The lighting system of claim 1, wherein the sealed region is
water-resistant or waterproof.
10. The lighting system of claim 1, further comprising a plurality
of control elements each (i) electrically connected to at least one
light-emitting string and (ii) configured to utilize power supplied
from the power conductors to control the current to the at least
one light-emitting string to which it is electrically
connected.
11. The lighting system of claim 10, wherein the plurality of
control elements are disposed within the sealed region.
12. The lighting system of claim 10, wherein each partial lighting
system comprises one or more of the control elements.
13. The lighting system of claim 1, further comprising,
electrically connected to the first and second power conductors, a
power supply for powering the light-emitting elements.
14. The lighting system of claim 1, further comprising a polymeric
bottom housing disposed over the second surface of the
substrate.
15. The lighting system of claim 14, wherein at least a portion of
the bottom housing is in contact with the top housing to enclose at
least a portion of the substrate, one or more of the light-emitting
strings, one or more of the conductive traces, at least a portion
of the first power conductor, and at least a portion of the second
power conductor.
16. The lighting system of claim 1, wherein a weight per area of
the lighting system is less than 5 kg/m.sup.2.
17. The lighting system of claim 1, wherein at least a portion of
the top housing is configured as a diffuser for a wavelength of
light emitted by the light-emitting elements.
18. The lighting system of claim 1, wherein a transmittance of the
top housing for a wavelength of light emitted by the light-emitting
elements is greater than 90%.
19. The lighting system of claim 1, wherein (i) the light-emitting
elements in each of the light-emitting strings are separated by a
substantially constant pitch and (ii) the top housing is spaced
apart from the light-emitting elements by an amount ranging from
the pitch between light-emitting elements to twice the pitch
between light-emitting elements.
20. The lighting system of claim 1, wherein at least one
light-emitting element emits substantially white light.
21. The lighting system of claim 1, wherein at least one
light-emitting element comprises a light-emitting diode.
22. The lighting system of claim 1, wherein the sealed region is at
least partially filled with a flexible transparent material having
a transmittance of at least 90% to a wavelength of light emitted by
the light-emitting elements.
23. The lighting system of claim 1, wherein the top housing
comprises a plurality of shaped regions each associated with a
light-emitting element.
24. The lighting system of claim 1, further comprising an optical
element disposed between the light-emitting elements and the top
housing.
25. The lighting system of claim 1, wherein (i) the top housing
defines a plurality of shaped regions, (ii) each shaped region is
associated with a light-emitting element and forms at least a
portion of an optical element thereover, and (iii) the top housing
has a transmittance greater than 90% to a wavelength of light
emitted by the light-emitting elements.
26. The lighting system of claim 1, wherein the lighting system is
flexible.
27. The lighting system of claim 1, wherein the top housing
comprises a transparent flexible material.
28. The lighting system of claim 27, wherein the transparent
flexible material comprises at least one of silicone, polyurethane,
or epoxy.
29. The lighting system of claim 1, wherein the top housing
conformally coats at least a portion of the first surface of the
light sheet.
30. The lighting system of claim 1, wherein at least one
light-emitting element is coupled to one or more of the conductive
traces with an anisotropic conductive adhesive, the anisotropic
conductive adhesive being activatable via application of at least
one of pressure, heat, or a magnetic field.
31. The lighting system of claim 1, wherein the top housing
conformally coats at least one light-emitting element.
32. The lighting system of claim 1, wherein at least a portion of
the top housing is transparent to a wavelength of light emitted by
the light-emitting elements.
33. The lighting system of claim 32, wherein the top housing
conformally coats at least a portion of the first surface of the
light sheet.
34. The lighting system of claim 33, wherein the top housing
conformally coats at least one light-emitting element.
35. The lighting system of claim 33, further comprising: a
plurality of control elements each (i) electrically connected to at
least one light-emitting string and (ii) configured to utilize
power supplied from the power conductors to control the current to
the at least one light-emitting string to which it is electrically
connected, wherein the plurality of control elements are disposed
within the sealed region; and an electrical connector (i)
electrically connected to at least one of the first or second power
conductors, (ii) terminating outside of the sealed region, and
(iii) configured to receive a complementary connector or wire
electrically connected to an external power source.
36. The lighting system of claim 35, wherein the top housing
conformally coats at least one light-emitting element.
37. The lighting system of claim 32, wherein the top housing
comprises a plurality of shaped regions each associated with a
light-emitting element and spaced-apart therefrom.
38. The lighting system of claim 37, further comprising: a
plurality of control elements each (i) electrically connected to at
least one light-emitting string and (ii) configured to utilize
power supplied from the power conductors to control the current to
the at least one light-emitting string to which it is electrically
connected, wherein the plurality of control elements are disposed
within the sealed region; and an electrical connector (i)
electrically connected to at least one of the first or second power
conductors, (ii) terminating outside of the sealed region, and
(iii) configured to receive a complementary connector or wire
electrically connected to an external power source.
39. The lighting system of claim 1, wherein a transmittance of at
least a portion of the top housing to a wavelength of light emitted
by the light-emitting elements is greater than 75%.
40. The lighting system of claim 1, further comprising an
electrical connector (i) electrically connected to least one of the
first or second power conductors and (ii) terminating outside of
the sealed region and configured to receive a complementary
connector or wire electrically connected to an external power
source.
41. The lighting system of claim 1, further comprising: a plurality
of control elements each (i) electrically connected to at least one
light-emitting string and (ii) configured to utilize power supplied
from the power conductors to control the current to the at least
one light-emitting string to which it is electrically connected,
wherein the plurality of control elements are disposed within the
sealed region; and an electrical connector (i) electrically
connected to at least one of the first or second power conductors,
(ii) terminating outside of the sealed region, and (iii) configured
to receive a complementary connector or wire electrically connected
to an external power source.
42. The lighting system of claim 1, wherein at least a portion of
the light emitted by the light-emitting elements is transmitted
through the polymeric top housing.
43. The lighting system of claim 42, further comprising a diffuser
disposed over the polymeric top housing.
44. The lighting system of claim 1, further comprising a diffuser
disposed over the polymeric top housing.
Description
FIELD OF THE INVENTION
In various embodiments, the present invention generally relates to
electronic devices, and more specifically to array-based electronic
devices.
BACKGROUND
Solid-state lighting is an attractive alternative to incandescent
and fluorescent lighting systems for a wide range of lighting
applications because of its relatively higher efficiency,
robustness, and long life. However, conventional solid-state
lighting systems featuring light-emitting diodes (LEDs) have a
number of limitations related to thermal management of heat
generated by the LEDs and the need to control the distribution of
light and ensure low glare.
In many lighting applications it is desirable to have lighting
systems or luminaires that are thin, low-volume, and lightweight in
order to meet certain aesthetic design requirements or so that the
lighting system is unobtrusive. In other applications it is
desirable to be able to conform the illumination source to a curved
surface. Current LED systems generally include LEDs that are
operated at relatively high current and thus very high brightness.
High-current operation is often preferred in order to reduce the
LED count and thus reduce the overall cost of the lighting system.
However, this results in the generation of significant amounts of
heat that must be extracted from the LED. In contrast to
incandescent lamps, which radiate heat into the environment, the
heat from LEDs in large measure must be extracted by conduction,
which generally requires relatively large amounts of material with
a high thermal conductivity, such as metal core printed circuit
boards (MCPCBs), heat sinks, and in some cases active (e.g.,
forced-air) cooling. Such thermal-management solutions typically
are not sufficiently flexible to permit conforming to curved
surfaces, and they take up significantly more space than the LEDs
themselves, resulting in increased size and volume of LED-based
lighting systems. These solutions may also increase system cost and
potentially reduce reliability and operational lifetime of the
lighting system. The high junction temperatures associated with
high-current operation also reduce LED lifetime.
Furthermore, if not appropriately managed, high-brightness
illumination sources do not provide the desired light distribution
pattern and may produce significant and unacceptable levels of
glare. Such optical challenges have been addressed in a number of
ways. For example, many lighting systems utilize a diffuser in
front of the LEDs, but in order to effectively reduce pixelization
(i.e., the visualization of the individual LEDs), the diffuser must
have relatively low transmittance, which decreases efficiency. Some
lighting systems utilize a large mixing volume for the emitted
light, which increases the size and cost of the illumination
system, or utilize relatively sophisticated and costly optics to
control the light-distribution pattern.
Thin, low-volume, and lightweight lighting elements are also
beneficial from a building design and cost perspective. Virtually
all buildings require unoccupied space to support heating,
ventilation, and air conditioning (HVAC) systems, electrical and
communications wiring, plumbing, and other facilities. From a cost
perspective it is desirable to minimize this unoccupied space,
which often results in these spaces becoming very crowded and
densely packed, which can lead to difficulties in initial
installation and subsequent repair and modification of the systems
within the space. In some construction processes, lighting is
installed closer to the end of the project, in which case the
unoccupied spaces may already be substantially filled, resulting in
significant installation difficulty. Lighting systems that require
significant volume in the unoccupied space may thus increase the
building cost by requiring additional unoccupied space, or pose
installation challenges if sufficient space has not been allotted
in advance.
Space constraints also apply in building renovation. In these cases
the spacing between floors is generally fixed and cannot be
changed. In particular, many older buildings were not designed to
support the required range of facilities in more modern buildings.
More unoccupied space can sometimes be created, but typically at
the expense of the occupied space, for example by reducing the
ceiling height.
In view of the foregoing, a need exists for systems and techniques
enabling the low-cost design and manufacture of compact, reliable,
high-brightness lighting systems having low glare and the ability
to produce different light-distribution patterns.
SUMMARY
In accordance with certain embodiments of the present invention,
lighting systems incorporate flexible light sheets having
light-emitting elements (e.g., bare-die light-emitting diodes)
thereon. Top and or bottom housings, either or both of which may be
polymeric, are utilized to seal at least portions of the light
sheets and form sealed regions that may be water-resistant or
waterproof. The housings may also be shaped to reflect, diffuse,
and/or shape the light emitted by the light-emitting elements. The
housings may even define structural features such as protruding
ribs for mechanical stability. While most, if not all, of the
light-emitting elements of the light sheets are preferably safely
located within the sealed regions, the lighting systems typically
incorporate conductive couplings that extend out of the sealed
regions (without disrupting the seal over the light-emitting
elements) and enable the provision of power from an external power
source to the light-emitting elements. Lighting systems in
accordance with embodiments of the invention may thus be
advantageously deployed in harsher and/or moist environments where
exposure to dirt, dust, moisture, etc. is possible or frequent. The
lighting systems may be fabricated in bulk by, e.g., roll-to-roll
processes and even separated from larger "sheets" of the lighting
device components, preferably without disrupting the seal on and/or
around each individual lighting system (or "partial" lighting
system). As used herein, a "sealed region" refers to a portion of a
light sheet or lighting system having a periphery at least
partially defined by a seal between two housings, a housing and the
light sheet, and/or a housing, light sheet, and/or another sealing
material (e.g., a transparent material disposed between the light
sheet and a housing. A sealed region may also include a portion of
a light sheet coated with a housing, i.e., the housing may be a
coating or sealant material conformally or non-conformally coating
(and thus directly contacting) the portion of the light sheet (and,
e.g., light-emitting elements, conductive traces, etc. on the light
sheet) thereunder.
In an aspect, embodiments of the invention feature a lighting
system including or consisting essentially of a substantially
planar flexible substrate having a first surface and a second
surface opposite the first surface, first and second spaced-apart
power conductors disposed over the first surface of the substrate,
a plurality of light-emitting strings forming a two-dimensional
array over the first surface of the substrate, a plurality of
conductive traces disposed over the first surface of the substrate,
a polymeric top housing disposed over the first surface of the
substrate, and one or more conductive couplings for supplying power
from an external power source to the light-emitting strings. Each
light-emitting string (i) includes or consists essentially of a
plurality of interconnected light-emitting elements spaced along
the light-emitting string, (ii) has a first end electrically
coupled to the first power conductor, and (iii) has a second end
electrically coupled to the second power conductor. The power
conductors supply power to each of the light-emitting strings. Each
conductive trace electrically interconnects two light-emitting
elements, or electrically connects a light-emitting element to a
power conductor. The top housing seals (e.g., gaplessly seals),
within a sealed region between the top housing and the substrate,
the plurality of light-emitting strings, the plurality of control
elements, the plurality of conductive traces, at least a portion of
the first power conductor, and at least a portion of the second
power conductor. One or more of the conductive couplings extend
from within the sealed region to outside of the sealed region.
Embodiments of the invention may include one or more of the
following in any of a variety of combinations. The sealed region
may be water-resistant or waterproof. The sealed region may include
or consist essentially of multiple individually sealed
"sub-regions" each at least partially sealed from the others. The
lighting system may include a plurality of control elements each
(i) electrically connected to at least one light-emitting string
and (ii) configured to utilize power supplied from the power
conductors to control the current to the at least one
light-emitting string to which it is electrically connected. One or
more (or even all) of the control elements may be disposed within
the sealed region. A plurality of additional conductive traces may
be disposed over the first surface of the substrate. Each
additional conductive trace may (i) electrically interconnect a
light-emitting element and a control element, or (ii) electrically
connect a control element to a power conductor. The control
elements and the additional conductive traces may be disposed
within the sealed region. The first and second power conductors may
be disposed entirely within the sealed region. The first and second
power conductors may extend along opposing edges of the first
surface of the substrate. The first and second power conductors may
extend in a first direction, and at least a portion of each of the
plurality of light-emitting strings may extend in a second
direction not parallel to (e.g., perpendicular to) the first
direction. The top housing may be disposed in contact with, in the
sealed region, the plurality of light-emitting strings, the
plurality of control elements, the plurality of conductive traces,
the at least a portion of the first power conductor, and/or the at
least a portion of the second power conductor. The top housing may
be spaced apart from the light-emitting strings and at least some
of the conductive traces in the sealed region.
The lighting system may include a power supply for powering the
light-emitting elements and that is electrically connected to the
first and second power conductors. The power supply may be disposed
within or outside of the sealed region. The power supply may
include or consist essentially of a battery. The power supply may
be configured to provide a substantially constant voltage to the
power conductors. At least one conductive coupling may be a portion
of the first power conductor and/or a portion of the second power
conductor. At least one conductive coupling may be a wire
electrically connected to at least one of the first or second power
conductors within the sealed region and extending outside of the
sealed region. At least one conductive coupling may include or
consist essentially of a conductive element (e.g., a rivet, staple,
or crimp-type connector) piercing through at least one of the top
housing or the substrate and making electrical contact to at least
one of the first or second power conductors. At least one
conductive coupling may include or consist essentially of an
electrical connector terminating outside of the sealed region and
configured to receive a complementary connector or wire
electrically connected to the external power source.
The lighting system may include a polymeric bottom housing disposed
over the second surface of the substrate (i.e., with the substrate
disposed between the top and bottom housings). At least a portion
of the bottom housing may contact the second surface of the
substrate to form a second sealed region disposed between the
bottom housing and the second surface of the substrate. The second
sealed region may include or consist essentially of multiple
individually sealed "sub-regions" each at least partially sealed
from the others. The sealed region and the second sealed region may
be water-resistant or waterproof. The bottom housing may be spaced
away from the second surface of the substrate in the second sealed
region. The bottom housing may be in contact with the second
surface of the substrate in at least a portion of the second sealed
region. The bottom housing may include or consist essentially of
polyester, acrylic, polystyrene, polyethylene, polyimide,
polyethylene naphthalate, polyethylene terephthalate,
polypropylene, polycarbonate, acrylonitrile butadiene styrene,
polyurethane, silicone, and/or polydimethylsiloxane.
At least a portion of the bottom housing may contact the top
housing (instead of or in addition to contacting the substrate) to
form a second sealed region disposed between the bottom housing and
the second surface of the substrate. The sealed region and the
second sealed region may be water-resistant or waterproof. The
bottom housing may be spaced away from the second surface of the
substrate in the second sealed region. The bottom housing may be in
contact with the second surface of the substrate in at least a
portion of the second sealed region. At least a portion of the
bottom housing may define a plurality of protruding ribs. The
bottom housing may include or consist essentially of polyester,
acrylic, polystyrene, polyethylene, polyimide, polyethylene
naphthalate, polyethylene terephthalate, polypropylene,
polycarbonate, acrylonitrile butadiene styrene, polyurethane,
silicone, and/or polydimethylsiloxane.
The lighting system may include (i) control circuitry configured to
control at least one emission characteristic of the light-emitting
elements, and/or (ii) communication circuitry configured to
transmit information to or from the lighting system. The at least
one emission characteristic may include or consist essentially of a
correlated color temperature (CCT), a color rendering index (CRI),
R9, a luminous flux, a light-output power, a spectral power
density, a radiant flux, a light-distribution pattern, and/or an
angular color uniformity. The lighting system may have an ingress
protection rating of at least IP 65, as specified by International
Protection Marking in International Electrotechnical Commission
(IEC) standard 60529. The plurality of light-emitting strings may
form a fixed pattern in the shape of one or more symbols and/or
letters. The weight per area of the lighting system may be less
than 5 kg/m.sup.2, less than 3 kg/m.sup.2, or less than 1.5
kg/m.sup.2. The thickness of the lighting system (including the top
housing and/or a bottom housing) may be less than 25 mm, less than
15 mm, less than 10 mm, or less than 5 mm. At least a portion of
the top housing may be configured as a diffuser for a wavelength of
light emitted by the light-emitting elements. A transmittance of
the top housing for a wavelength of light emitted by the
light-emitting elements may be greater than 90%. The light-emitting
elements in each of the light-emitting strings may be separated by
a substantially constant pitch. The top housing may be spaced apart
from the light-emitting elements by an amount ranging from the
pitch between light-emitting elements to twice the pitch between
light-emitting elements.
At least one light-emitting element may emit substantially white
light. A correlated color temperature of the substantially white
light may be in the range of 2000 K to 10,000 K. At least one
light-emitting element may include or consist essentially of a
bare-die light-emitting diode. At least one light-emitting element
may include or consist essentially of a packaged light-emitting
diode. In at least one light-emitting string, each light-emitting
element may be coupled to one or more conductive traces via solder
and/or an adhesive. Each light-emitting element in one or more
light-emitting strings may be coupled to one or more conductive
traces via an anisotropic conductive adhesive. The conductive
traces may include or consist essentially of copper, brass,
aluminum, silver, and/or gold. The thickness of the conductive
traces may be less than 50 .mu.m, and the substrate may include or
consist essentially of polyethylene terephthalate. The sealed
region may include an inert gas therewithin. The sealed region may
be at least partially filled with a flexible transparent material
(which may be separate and discrete from the top housing, bottom
housing, and/or substrate) having a transmittance of at least 90%
to a wavelength of light emitted by the light-emitting elements.
The sealed region may be filled with the transparent material
(i.e., the transparent material may occupy any space between the
light sheet and the top housing in the sealed region). The
transparent material may include or consist essentially of
silicone, polyurethane, and/or epoxy. A desiccant may be disposed
in the sealed region. At least a portion of the top housing may
define a plurality of protruding ribs.
At least a portion of an interior surface of the top housing may
have a reflectance greater than 90% to a wavelength of light
emitted by the light-emitting elements, and/or at least a portion
of the substrate may have a transmittance greater than 90% to a
wavelength of light emitted by the light-emitting elements. A
portion of the top housing may be shaped to reflect light emitted
by the light-emitting elements toward the substrate. The top
housing may include or consist essentially of a plurality of shaped
regions each associated with a light-emitting element. Each shaped
region may include or consist essentially of a hemisphere, a
portion of a sphere, or a paraboloid. Each shaped region may
include or consist essentially of a paraboloid, and the
light-emitting element associated therewith may be positioned at a
focal point of the paraboloid. An optical element may be disposed
between the light-emitting elements and the top housing. A
plurality of optical elements may be disposed between the
light-emitting elements and the top housing, and each optical
element may be associated with one or more light-emitting elements.
The top housing may define a plurality of shaped regions, each
shaped region may be associated with a light-emitting element and
may form at least a portion of an optical element thereover, and
the top housing may have a transmittance greater than 90% to a
wavelength of light emitted by the light-emitting elements. The
shaped regions may each include or consist essentially of a
hemisphere, a portion of a sphere, or a paraboloid. A flexible
transparent material having a transmittance of at least 90% to a
wavelength of light emitted by the light-emitting elements may be
disposed between the polymeric top housing and the light-emitting
elements. The transparent material may include or consist
essentially of silicone, polyurethane, and/or epoxy. The
transparent material may have a refractive index of at least
1.4.
The lighting system may be separable, via a cut spanning the first
and second power conductors and not crossing a light-emitting
string, into two individually operable partial lighting systems.
Each partial lighting system may include or consist essentially of
(i) one or more light-emitting strings, (ii) portions of the first
and second power conductors configured to supply power to and
thereby illuminate the one or more light-emitting strings of the
partial lighting system, (iii) a sealed region defined by a seal
between a portion of the top housing and the substrate, and (iv)
extending from within the sealed region to outside of the sealed
region, one or more of the conductive couplings. One or more
control elements may be disposed in each partial lighting system.
Each control element may be (i) electrically connected to at least
one light-emitting string and (ii) configured to utilize power
supplied from the power conductors to control the current to the at
least one light-emitting string to which it is electrically
connected. The lighting system may be flexible. The top housing may
include or consist essentially of polyester, acrylic, polystyrene,
polyethylene, polyimide, polyethylene naphthalate, polyethylene
terephthalate, polypropylene, polycarbonate, acrylonitrile
butadiene styrene, polyurethane, silicone, and/or
polydimethylsiloxane.
The top housing may include or consist essentially of a transparent
flexible material. The transparent material may include or consist
essentially of silicone, polyurethane, and/or epoxy. The top
housing may conformally coat at least a portion of the first
surface of the light sheet. At least one conductive coupling may be
configured to convey a communication or control signal to or from
the light sheet. The communication or control signal may include or
consist essentially of a light-intensity level, a correlated color
temperature (CCT), a color rendering index (CRI), a
luminous-intensity distribution, and/or an operational state of the
light sheet. One or more second conductive couplings configured to
convey a communication or control signal to or from the light sheet
may extend from within the sealed region to outside of the sealed
region. The communication or control signal may include or consist
essentially of a light-intensity level, a correlated color
temperature (CCT), a color rendering index (CRI), a
luminous-intensity distribution, and/or an operational state of the
light sheet.
In another aspect, embodiments of the invention feature a method
for manufacturing a lighting system. A light sheet is provided. The
light sheet includes or consists essentially of a substantially
planar flexible substrate having a first surface and a second
surface opposite the first surface, first and second spaced
spaced-apart power conductors disposed over the first surface of
the substrate, a plurality of light-emitting elements disposed over
the first surface of the substrate, and a plurality of conductive
traces disposed over the first surface of the substrate and each
(i) electrically interconnecting two light-emitting elements, or
(ii) electrically connecting a light-emitting element to a power
conductor. The light-emitting elements may be interconnected (e.g.,
serially connected) in one or more light-emitting strings.
Optionally, a polymeric bottom housing is provided below a bottom
surface of the light sheet. A polymeric top housing is provided
above a top surface of the light sheet opposite the bottom surface
of the light sheet. At least a portion of the top housing is sealed
to the light sheet and/or the bottom housing to form one or more
sealed regions containing the light-emitting elements.
Embodiments of the invention may include one or more of the
following in any of a variety of combinations. The bottom housing
may be provided, the at least a portion of the top housing may be
sealed to the light sheet, and at least a portion of the bottom
housing may be sealed to the light sheet. At least a portion of the
bottom housing may be sealed to the light sheet to thereby form one
or more second sealed regions disposed between the bottom of the
light sheet and the bottom housing. At least a portion of the
bottom housing may be sealed to the top housing. One or more of the
sealed regions may be filled with an inert gas. One or more of the
sealed regions may be partially or substantially filled with a
flexible transparent material having a transmittance of at least
90% to a wavelength of light emitted by the light-emitting
elements. The lighting system may be separated into a plurality of
individually operable partial lighting systems each including or
consisting essentially of (i) one or more light-emitting elements,
(ii) portions of the first and second power conductors configured
to supply power to and thereby illuminate the one or more
light-emitting elements of the partial lighting system, and (iii)
one or more of the sealed regions. The transparent material may
maintain (e.g., form a portion of) the seal between the top housing
and the light sheet and/or the bottom housing in the one or more
sealed regions notwithstanding the separation.
One or more conductive couplings for (i) supplying power from an
external power source to one or more light-emitting elements and/or
(ii) conveying a communication or control signal to or from the
light sheet may be provided. Each conductive coupling may extend
from within a sealed region to outside of the sealed region. The
communication or control signal may include or consist essentially
of a light-intensity level, a correlated color temperature, a color
rendering index, a luminous-intensity distribution, and/or an
operational state of the light sheet. The lighting system may be
separated into a plurality of individually operable partial
lighting systems each including or consisting essentially of (i)
one or more light-emitting elements, (ii) portions of the first and
second power conductors configured to supply power to and thereby
illuminate the one or more light-emitting elements of the partial
lighting system, (iii) one or more of the sealed regions, and (iv)
one or more of the conductive couplings. At least one conductive
coupling may be provided before the one or more sealed regions are
formed. At least one conductive coupling may be provided after the
one or more sealed regions are formed.
The lighting system may be separated into a plurality of
individually operable partial lighting systems each including or
consisting essentially of (i) one or more light-emitting elements,
(ii) portions of the first and second power conductors configured
to supply power to and thereby illuminate the one or more
light-emitting elements of the partial lighting system, and (iii)
one or more of the sealed regions. The light-emitting elements may
be interconnected to form a plurality of light-emitting strings.
Each light-emitting string (i) may comprise a plurality of
interconnected light-emitting elements spaced along the
light-emitting string, (ii) may have a first end electrically
coupled to the first power conductor, and (iii) may have a second
end electrically coupled to the second power conductor. The power
conductors may supply power to each of the light-emitting strings.
The light sheet may include thereon one or more control elements
each (i) electrically connected to a different light-emitting
string and (ii) configured to utilize power supplied from the power
conductors to provide a substantially constant current to the
light-emitting string to which it is electrically connected.
Providing the top housing may include, before the one or more
sealed regions are formed, shaping the top housing to define (i)
one or more protruding ribs and/or (ii) one or more optical
elements. Providing the top housing may include, before the one or
more sealed regions are formed, coating at least a portion of the
top housing with a coating having a reflectance greater than 90% to
a wavelength of light emitted by the light-emitting elements.
Each sealed region may be water-resistant or waterproof. Sealing at
least a portion of the top housing to the light sheet and/or the
bottom housing may include or consist essentially of heat welding,
high-frequency welding, ultrasonic welding, laser welding, heat
staking, gluing, and/or taping. Formation of the one or more sealed
regions may include or consist essentially of laminating the top
housing to the top surface of the light sheet. A transparent
material having a transmittance of at least 90% to a wavelength of
light emitted by the light-emitting elements may be disposed over
the first surface of the substrate. The transparent material may be
provided before forming the one or more sealed regions. The
transparent material may include or consist essentially of
silicone, polyurethane, and/or epoxy. The transparent material may
be disposed over the substrate via dip coating, spray coating,
brush coating, and/or printing. The transparent material may
substantially conform to a non-planar topography of the
light-emitting elements thereunder. The top surface of the
transparent material may be planar notwithstanding a non-planar
topography of the light-emitting elements thereunder. The
transparent material may also be disposed over at least a portion
of the second surface of the substrate. The transparent material
may form a water-resistant or waterproof coating. One or more
sealed regions may each have an ingress protection rating of at
least IP 65, as specified by International Protection Marking in
International Electrotechnical Commission (IEC) standard 60529.
The light sheet may be provided on a first roll, the top housing
may be provided on a second roll, and the top housing may be sealed
to the light sheet. Sealing the top housing to the light sheet may
include or consist essentially of, in a roll-to-roll process, (a)
feeding light sheet from the first roll and top housing from the
second roll to a mating point, and at the mating point or
thereafter, (b) sealing the mated light sheet and top housing. The
lighting system may be separated into a plurality of individually
operable partial lighting systems each including or consisting
essentially of (i) one or more light-emitting elements, (ii)
portions of the first and second power conductors configured to
supply power to and thereby illuminate the one or more
light-emitting elements of the partial lighting system, and (iii)
one or more of the sealed regions. One or more conductive couplings
each (i) supplying power from an external power source to one or
more light-emitting elements and/or (ii) conveying a communication
or control signal to or from the light sheet may be provided. Each
conductive coupling may extend from within a sealed region to
outside of the sealed region. At least one conductive coupling may
be provided before the one or more sealed regions are formed. At
least one conductive coupling may be provided after the one or more
sealed regions are formed. Each partial lighting system may include
one or more of the conductive couplings. The communication or
control signal may include or consist essentially of a
light-intensity level, a correlated color temperature, a color
rendering index, a luminous-intensity distribution, or an
operational state of the light sheet.
The light sheet may be provided on a first roll, the top housing
may be provided on a second roll, the bottom housing may be
provided on a third roll, and sealing the top housing to the light
sheet and/or the bottom housing may include or consist essentially
of, in a roll-to-roll process, (a) feeding light sheet from the
first roll, top housing from the second roll, and bottom housing
from the third roll to a mating point, and at the mating point or
thereafter, (b) sealing the top housing to at least one of the
light sheet or the bottom housing. The lighting system may be
separated into a plurality of individually operable partial
lighting systems each including or consisting essentially of (i)
one or more light-emitting elements, (ii) portions of the first and
second power conductors configured to supply power to and thereby
illuminate the one or more light-emitting elements of the partial
lighting system, and (iii) one or more of the sealed regions. One
or more conductive couplings each (i) supplying power from an
external power source to one or more light-emitting elements and/or
(ii) conveying a communication or control signal to or from the
light sheet may be provided. Each conductive coupling may extend
from within a sealed region to outside of the sealed region. At
least one conductive coupling may be provided before the one or
more sealed regions are formed. At least one conductive coupling
may be provided after the one or more sealed regions are formed.
Each partial lighting system may include one or more of the
conductive couplings. The communication or control signal may
include or consist essentially of a light-intensity level, a
correlated color temperature, a color rendering index, a
luminous-intensity distribution, or an operational state of the
light sheet.
These and other objects, along with advantages and features of the
invention, will become more apparent through reference to the
following description, the accompanying drawings, and the claims.
Furthermore, it is to be understood that the features of the
various embodiments described herein are not mutually exclusive and
can exist in various combinations and permutations. Reference
throughout this specification to "one example," "an example," "one
embodiment," or "an embodiment" means that a particular feature,
structure, or characteristic described in connection with the
example is included in at least one example of the present
technology. Thus, the occurrences of the phrases "in one example,"
"in an example," "one embodiment," or "an embodiment" in various
places throughout this specification are not necessarily all
referring to the same example. Furthermore, the particular
features, structures, routines, steps, or characteristics may be
combined in any suitable manner in one or more examples of the
technology. As used herein, the terms "about," "approximately," and
"substantially" mean.+-.10%, and in some embodiments, .+-.5%. The
term "consists essentially of" means excluding other materials that
contribute to function, unless otherwise defined herein.
Nonetheless, such other materials may be present, collectively or
individually, in trace amounts.
Herein, two components such as light-emitting elements and/or
optical elements being "aligned" or "associated" with each other
may refer to such components being mechanically and/or optically
aligned. By "mechanically aligned" is meant coaxial or situated
along a parallel axis. By "optically aligned" is meant that at
least some light (or other electromagnetic signal) emitted by or
passing through one component passes through and/or is emitted by
the other.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, like reference characters generally refer to the
same parts throughout the different views. Also, the drawings are
not necessarily to scale, emphasis instead generally being placed
upon illustrating the principles of the invention. In the following
description, various embodiments of the present invention are
described with reference to the following drawings, in which:
FIG. 1A is a circuit diagram of a portion of a light sheet in
accordance with various embodiments of the invention;
FIGS. 1B and 1C are schematic plan views of light sheets in
accordance with various embodiments of the invention;
FIGS. 2A and 2B are schematic cross-sections of lighting devices in
accordance with various embodiments of the invention;
FIG. 2C is a schematic cross-section of a portion of a lighting
device in accordance with various embodiments of the invention;
FIGS. 2D-2F are schematic cross-sections of lighting devices in
accordance with various embodiments of the invention;
FIGS. 3A and 3B are a schematic cross-section (FIG. 3A) and a
partial schematic plan view (FIG. 3B) of a lighting device in
accordance with various embodiments of the invention;
FIGS. 3C-3E are schematic cross-sections of lighting devices in
accordance with various embodiments of the invention;
FIG. 4 is a flowchart of a method of fabrication of lighting
devices in accordance with various embodiments of the
invention;
FIG. 5A is a schematic cross-section of a light sheet in accordance
with various embodiments of the invention;
FIGS. 5B and 5C are schematic cross-sections of portions of a
lighting-device housing in two stages of manufacture in accordance
with various embodiments of the invention;
FIGS. 5D-5F are schematic cross-sections of electrical connections
to light sheets in accordance with various embodiments of the
invention;
FIG. 5G is a schematic cross-section of a peripheral portion of a
lighting device in accordance with various embodiments of the
invention;
FIGS. 5H-5J are schematic cross-sections of electrical connections
to light sheets in accordance with various embodiments of the
invention;
FIGS. 5K and 5L are schematic cross-sections of a lighting device
during two stages of manufacture in accordance with various
embodiments of the invention;
FIG. 6A is a schematic plan view of a sheet separable into multiple
lighting devices in accordance with various embodiments of the
invention;
FIGS. 6B-6D are schematic cross-sections of sheets separable into
multiple lighting devices in accordance with various embodiments of
the invention;
FIGS. 7 and 8 are schematic diagrams of roll-to-roll processing
apparatuses for the fabrication of lighting devices in accordance
with various embodiments of the invention;
FIG. 9A is a schematic cross-section of a lighting device in
accordance with various embodiments of the invention;
FIGS. 9B and 9C are schematic plan views of sheets separable into
multiple lighting devices in accordance with various embodiments of
the invention;
FIG. 9D is a schematic cross-section of a portion of a lighting
device having a crimp-type or punch-type electrical connection in
accordance with various embodiments of the invention;
FIGS. 9E and 9F are schematic plan views of a sheet separable (FIG.
9E) and separated (FIG. 9F) into multiple lighting devices in
accordance with various embodiments of the invention;
FIGS. 10A and 10B are schematic cross-sections of a laminated
lighting device during two stages of manufacture in accordance with
various embodiments of the invention;
FIG. 10C is a schematic cross-section of a laminated lighting
device in accordance with various embodiments of the invention;
FIG. 10D is a schematic diagram of a roll-to-roll processing
apparatus for the fabrication of laminated lighting devices in
accordance with various embodiments of the invention;
FIG. 11A is a schematic diagram of a roll-to-roll processing
apparatus for the fabrication of coated lighting devices in
accordance with various embodiments of the invention;
FIGS. 11B-11D are schematic cross-sections of coated lighting
devices in accordance with various embodiments of the invention;
and
FIGS. 12A-12D are schematic diagrams of electrical connectivity
between components of lighting systems in accordance with various
embodiments of the invention.
DETAILED DESCRIPTION
Various embodiments of the present invention feature a thin light
sheet that does not require any additional heat sinking or thermal
management. In some embodiments, the light sheet may also be
flexible and may be curved or folded to achieve one or more
specific characteristics or attributes, for example, to permit
manufacture of a compact, foldable system and/or to achieve a
specific light-distribution pattern. In some embodiments of the
present invention, the light sheet typically includes or consists
essentially of an array of light-emitting elements (LEEs)
electrically coupled by conductive elements formed on a flexible
substrate, for example as described in U.S. patent application Ser.
No. 13/799,807, filed Mar. 13, 2013 (the '807 application), or U.S.
patent application Ser. No. 13/970,027, filed Aug. 19, 2013 (the
'027 application), the entire disclosure of each of which is herein
hereby incorporated by reference.
FIG. 1A depicts an exemplary circuit topology of one embodiment of
a light sheet, in accordance with embodiments of the present
invention, which features conductive elements 160, at least two
power conductors 120, 121, multiple LEEs 140, and control elements
(CEs) 145. In some embodiments, LEEs 140 may be configured in a
regular periodic array, for example a substantially square or
rectangular array, where LEEs 140 are separated by pitch (or
"spacing") 123 in one direction (for example, a vertical or
intrastring direction) and by pitch 125 in a substantially
orthogonal direction (for example, a horizontal or interstring
direction). In some embodiments, pitch 125 is the same as or
substantially the same as pitch 123. While the geometrical layout
and pitches 123, 125 are described in connection with the circuit
schematic shown in FIG. 1A, such geometry, layout, and pitches are
not limitations of the present invention, and in other embodiments
the physical layout of the circuit elements may be different than
the circuit topology shown in FIG. 1A. Additionally, other
embodiments may have different circuit topologies, for example LEEs
140 may be electrically coupled in parallel, in a combination of
series and parallel, or any other arrangement. In some embodiments,
more than one group of electrically connected LEEs 140 may be
electrically coupled to one CE 145, while other embodiments may not
require any CEs 145. The specific circuit topology is not a
limitation of the present invention.
FIG. 1A shows two power conductors 120, 121, which may be used to
provide power to strings 150 of LEEs 140. Each string 150 may
include two or more electrically coupled LEEs 140. LEEs 140 in
string 150 may be electrically coupled in series, as shown in FIG.
1A; however, this is not a limitation of the present invention, and
in other embodiments other examples of electrical coupling may be
utilized, for example parallel connections or any combination of
series and parallel connections. FIG. 1A shows CE 145 connected in
series with LEEs 140 of string 150; however, this is not a
limitation of the present invention, and in other embodiments CE
145 may have different electrical coupling between power conductors
120, 121, or may be absent altogether. For example, in some
embodiments CE 145 may be separately electrically coupled to power
conductors 120, 121 and to the LEE string 150, while in other
embodiments each CE 145 may be electrically coupled to two or more
strings. The number of strings electrically coupled to each CE 145
is not a limitation of the present invention. Combinations of
structures described herein, as well as other electrical
connections, all fall within the scope of the present invention.
Power conductors 120, 121 may be used to provide power to strings
150, for example AC power, DC power, or power modulated by any
other means.
Referring to FIGS. 1B and 1C that depict schematics of exemplary
light sheets 110, a light sheet 110 may feature an array of LEEs
140 each electrically coupled between conductive traces 160, as
well as power conductors 120, 121 providing power to conductive
traces 160 and CEs 145, all of which are disposed over a substrate
165. As utilized herein, a "wiring board" refers to a substrate for
LEEs with or without additional elements such as conductive traces
or CEs. A wiring board may also be referred to as a light sheet or
a circuit board. FIG. 1B shows a portion of a light sheet 110. In
the exemplary embodiment depicted in FIG. 1B, power conductors 120,
121 are spaced apart from each other and light-emitting strings (or
simply "strings") 150 are connected in parallel across power
conductors 120, 121. In some embodiments, for example as shown in
FIG. 1B, strings 150 do not cross (i.e., intersect) each other. In
other words, power conductors 120, 121 are oriented in one
direction and strings 150 are oriented such that they span power
conductors 120, 121 in a different direction. As shown in FIG. 1B,
strings 150 are substantially perpendicular to power conductors
120, 121. However, this is not a limitation of the present
invention, and in other embodiments at least some segments (i.e.,
portions connecting two or more LEEs 140), or even the entire
strings 150, may define a line (not necessarily a straight line)
that is not perpendicular to power conductors 120, 121 yet is (at
least for an entire string 150) not parallel to power conductors
120, 121. In other embodiments, strings 150 may intersect, for
example one string 150 splitting into two or more strings 150, or
two or more strings 150 joining to form a reduced number of strings
150. In some embodiments, conductive elements 160 may cross over
each other without being electrically coupled to each other (i.e.,
they may be electrically insulated from each other), and in some
embodiments strings 150 may cross over or under each other without
being electrically coupled to each other. In some embodiments, all
or a portion of one or more strings 150 may extend outside of the
area bound by power conductors 120, 121. Various examples of string
geometries and conformations utilized in embodiments of the present
invention are described in the '807 and '027 applications.
As shown in FIGS. 1B and 1C, LEEs 140 may be positioned across
substrate 165 in a regular periodic array, although this is not a
limitation of the present invention, and in other embodiments LEEs
140 may occupy any positions on light sheet 110. Power conductors
120, 121 provide power to each LEE string, for example the string
150 encircled by the dashed line in FIG. 1B. Each LEE string 150
typically includes multiple conductive traces 160 that interconnect
multiple LEEs 140, as well as one or more CEs 145, which in FIG. 1B
is in series with LEEs 140. String 150 shown in FIG. 1B is a folded
string, i.e., a string that has three segments electrically coupled
in series but positioned as three adjacent segments. A string
segment is a portion of a string spanning all or a portion of the
region between power conductors 120, 121 in FIG. 1B. In light sheet
110, some string segments may include LEEs 140 while others do not.
However, in other embodiments the distribution and position of LEEs
140 along conductive elements 160 and string segments may be
different. In some embodiments, a string 150 may be a straight
string, i.e., a string with no folds, as shown in FIG. 1C. (For
simplicity, the example shown in FIG. 1C does not depict CEs 145.)
One end of string 150 is electrically coupled to power conductor
120, while the other end of string 150 is electrically coupled to
power conductor 121. As will be discussed, the number of segments
in a string 150 is not a limitation of the present invention.
Various examples of straight and folded strings utilized in
embodiments of the present invention are detailed in the '807 and
'027 applications.
FIGS. 1A and 1B illustrate three aspects in accordance with
embodiments of the present invention. The first is the multiple
strings 150 that are powered by the set of power conductors 120,
121. The second is the positional relationship between the
locations of LEEs 140 and CE 145, which is disposed between the
conductive traces 160 and between power conductors 120,121, such
that the pitch between LEEs 140 is not disrupted by the placement
or position of CE 145. The third is the inclusion of a CE 145 in
each string of series-connected LEEs 140. Combinations of these
three aspects enable light sheet 110 to be economically
manufactured in very long lengths, for example in a roll-to-roll
process, and cut to specified lengths, forming light sheets, while
maintaining the ability to tile, or place light sheets adjacent to
each other (e.g., in the length direction), with no or
substantially no change in pitch between LEEs 140 or in the optical
characteristics across the joint between two adjacent light sheets,
as discussed in more detail in the '807 and '027 applications.
In an exemplary embodiment, CE 145 is configured to maintain a
constant or substantially constant current through LEEs 140 of
string 150. For example, in some embodiments, a constant voltage
may be applied to power conductors 120, 121, which may, under
certain circumstances may have some variation, or the sum of the
forward voltages of LEEs 140 in different strings may be somewhat
different, for example as a result of manufacturing tolerances, or
the component and/or operational values of the element(s) within CE
145 may vary, for example as a result of manufacturing tolerances
or changes in operating temperature, and CE 145 acts to maintain
the current through LEEs 140 substantially constant in the face of
these variations. In other words, in some embodiments the input to
the light sheet is a constant voltage that is applied to power
conductors 120, 121, and CEs 145 convert the constant voltage to a
constant or substantially constant current through LEEs 140. The
design of CE 145 may be varied to provide different levels of
control or variation of the current through LEEs 140. In some
embodiments, CEs 145 may control the current through LEEs 140 to be
substantially constant with a variation of less than about .+-.25%.
In some embodiments, CEs 145 may control the current through LEEs
140 to be substantially constant with a variation of less than
about .+-.15%. In some embodiments, CEs 145 may control the current
through LEEs 140 to be substantially constant with a variation of
less than about .+-.10%. In some embodiments, CEs 145 may control
the current through LEEs 140 to be substantially constant with a
variation of less than about .+-.5%.
In some embodiments, CEs 145 may, in response to a control signal,
act to maintain a constant or substantially constant current
through LEEs 140 until instructed to change to a different constant
or substantially constant current, for example by an external
control signal. In some embodiments, as detailed herein, all CEs
145 on a sheet may act in concert, that is maintain or change the
current through all associated LEEs 140; however, this is not a
limitation of the present invention, and in other embodiments one
or more CEs 145 may be individually instructed and/or
energized.
In some embodiments LEEs 140 may include or consist essentially of
light-emitting diodes (LEDs) or lasers. In some embodiments, light
emitted from light sheet 110 is in the form of an array of bright
spots, or light-emission points, resulting in a pixelated pattern.
However, this is not a limitation of the present invention, and in
other embodiments light sheet 110 includes different types of light
emitters, for example organic LEDs (OLEDs). In some embodiments,
light sheet 110 may emit light homogeneously or substantially
homogeneously, for example light sheet 110 may include an array of
LEEs 140 behind an optic or diffuser that spreads the light from
LEEs 140 homogeneously or substantially homogeneously. In some
embodiments, light sheet 110 may include one or more OLEDs emitting
homogeneously or substantially homogeneously over light sheet
110.
In the embodiment depicted in FIG. 1B, LEEs 140 are distributed
substantially uniformly over light sheet 110; however, this is not
a limitation of the present invention, and in other embodiments,
LEEs 140 may have a non-uniform distribution. As will be
understood, the distributions of LEE 140 on light sheet 110 shown
in FIGS. 1B and 1C are not limitations of the present invention,
and other embodiments may have other distributions of LEEs 140. In
some embodiments, one or more portions of light sheet 110 may be
unpopulated with LEEs 140. In some embodiments, the distribution of
LEEs 140 on light sheet 110 is specifically chosen to achieve one
or more characteristics, for example optical, electrical, thermal
or the like, as described herein. In some embodiments, the
distribution of LEEs 140 on light sheet 110 may be chosen to create
a certain decorative look.
In some embodiments, light sheet 110 may also be cut to length, as
discussed in more detail in the '807 and '027 applications. For
example, in some embodiments of the present invention light sheet
110 may be cut between strings 150.
In some embodiments, light sheet 110 does not require any
additional thermal management or heat-sinking, i.e., the heat
generated by LEEs 140 is at least partially accommodated by the
structure of light sheet 110 itself, for example substrate 165
and/or conductive elements 160 and/or power conductors 120,
121.
In some embodiments of the present invention, substrate 165 is
substantially covered with an array of LEEs 140 interconnected by
conductive elements 160; however, in some embodiments one or more
portions of substrate 165 may not be populated with LEEs 140.
In some embodiments, all LEEs 140 in the lighting system may be
driven at the same or substantially the same current; however, this
is not a limitation of the present invention, and in other
embodiments different LEEs 140 or different groups of LEEs 140 may
be driven at different currents.
In some embodiments, all LEEs 140 in the lighting system may have
the same optical characteristics, for example luminous or radiant
flux, CCT, CRI, R9, spectral power distribution, light distribution
pattern, angular color uniformity, or the like; however, this is
not a limitation of the present invention, and in other embodiments
different LEEs 140 or different groups of LEEs 140 may have
different optical characteristics.
FIGS. 2A-2F depict exemplary lighting devices in accordance with
embodiments of the present invention, although alternative devices
or systems with similar functionality are also within the scope of
the invention. FIG. 2A shows a cross-sectional view of a lighting
device 200 of the present invention. (Conductive traces 160 are not
shown in FIGS. 2A-2F for clarity.) Lighting device 200 as shown is
designed to be installed into a ceiling grid system, for example a
T-grid 290, as shown in FIG. 2A; however; this is not a limitation
of the present invention; and in other embodiments other grid
systems may be used. In other embodiments, lighting device 200 may
be mounted using other techniques, for example it may be surface
mounted or suspended. Lighting device 200 includes a top housing
210, a bottom housing 220, and light sheet 110 that includes
substrate 165 and LEEs 140, as detailed above. As used herein, the
term "housing" broadly connotes any containment structure or medium
for fully overlying a top or bottom surface of the light sheet 110.
A housing may be rigid or flexible, polymeric or other material
(e.g., glass), and may interconnect with or be bondable to the
light sheet or to another housing over the opposite surface of the
light sheet to form a seal, e.g., a water-tight or water-resistant
seal, around at least a portion of the light sheet. In some
embodiments of the present invention, top housing 210 and bottom
housing 220 are fabricated from plastic, for example polyester,
acrylic, polystyrene, polyethylene, polyimide, polyethylene
naphthalate (PEN), polyethylene terephthalate (PET), polypropylene,
polycarbonate, acrylonitrile butadiene styrene (ABS), or the like.
In some embodiments of the present invention top housing 210 and
bottom housing 220 are fabricated by molding or thermoforming.
In some embodiments of the present invention, the materials of
construction, for example substrate 165, top housing 210 and/or
bottom housing 220, include or consist essentially of materials
having low flammability. One measure of flammability is defined by
Underwriter Laboratories (UL) standard 94. UL94 includes various
rating levels, for example UL94 V-1, UL94 V-2, UL94 V-0, UL94 V5B,
UL94 V5A, and the like. In some embodiments of the present
invention, the materials of construction are chosen to provide a
certain level of flame retardance to the lighting system, for
example, as measured by the UL94 flammability standard. In some
embodiments of the present invention, the lighting system, for
example as shown in FIGS. 2A, 2C-2F, 3A-3E, 6B-6D and the like, the
lighting system has a UL94 rating of at least UL94 V-1, or at least
UL94 V-0, or at least UL94 5B, or at least UL94 5A.
In preferable embodiments of the present invention, all or a
portion of bottom housing 220 is transparent to a wavelength of
light emitted by LEEs 140, for example having a transmittance to a
wavelength of light emitted by LEEs 140 of at least 75%, or at
least 85%, or at least 95%. In some embodiments of the present
invention, all or a portion of bottom housing 220 may include a
diffuser, for example to diffuse or scatter a wavelength of light
emitted by LEEs 140.
In some embodiments of the present invention, all or a portion of
top housing 210 is transparent to a wavelength of light emitted by
LEEs 140, for example having a transmittance to a wavelength of
light emitted by LEEs 140 of at least 75%, or at least 85%, or at
least 95%, while in other embodiments all or a portion of top
housing 210 may be translucent or opaque to a wavelength of light
emitted by LEEs 140. In some embodiments of the present invention,
all or a portion of housing 210 or an inner surface 211 of top
housing 210 may be reflective to a wavelength of light emitted by
LEEs 140, for example having a reflectance to a wavelength of light
emitted by LEEs 140 of at least 75%, or at least 85%, or at least
95%.
In some embodiments, portions of top housing 210 and/or bottom
housing 220 may be ribbed (i.e., have protruding segments), e.g.,
have one or more ribs 230 in FIG. 2A, or otherwise structured to
provide rigidity to lighting device 200.
In some embodiments of the present invention, top housing 210 and
bottom housing 220 may be joined at the periphery of lighting
device 200, for example in the region identified as 240 in FIG. 2A.
In some embodiments of the present invention, top housing 210 and
bottom housing 220 may be joined by heat welding, high-frequency
welding, ultrasonic welding, laser welding, adhesive, glue, tape,
or the like. In some embodiments of the present invention, top
housing 210 and/or bottom housing 220 may be joined to light sheet
110 or to each other within the periphery of lighting device
200.
In some embodiments of the present invention, housings 210, 220 may
be configured to protect light sheet 110, for example to provide
mechanical protection, protection from dust, water, etc. One method
for rating different levels of environmental protection is an IP
rating as specified by International Protection Marking in
International Electrotechnical Commission (IEC) standard 60529,
providing classification of degrees of protection provided by
enclosures for electrical equipment, the entirety of which is
hereby incorporated by reference herein. In some embodiments of the
present invention, lighting device 200 may have any IP rating, for
example from IP00 to IP 69k, or any other IP rating. In some
embodiments of the present invention, lighting device 200 has an IP
44 rating, or an IP65 rating or an IP66 rating or an IP67 rating or
an IP68 rating. In general for an IP XY rating, "X" indicates the
level of protection for access to electrical parts and ingress to
solid foreign objects, while "Y" indicates the level of protection
for ingress of harmful water. For example, an IP44 rating provides
access and ingress protection for objects greater than about 1 mm
and protection from water splashing on the system. In another
example, an IP66 rating provides a dust-tight enclosure and
protection from water jets incident on the system. Specific details
of the requirements and test method are detailed within the IP
specification.
In some embodiments of the present invention, the interior region
formed by housings 210, 220 may additionally contain a desiccant to
absorb excess moisture and/or water vapor and prevent degradation
or corrosion of light sheet 110 and associated components. In some
embodiments of the present invention, the interior region formed by
housings 210, 220 may be purged with an inert gas, for example
nitrogen or argon, prior to sealing to reduce the moisture and/or
water vapor concentration and prevent degradation or corrosion of
light sheet 110 and associated components.
In some embodiments of the present invention, the interior region
formed by housings 210, 220 may be evacuated to a relatively low
pressure, or may be filled with air. In some embodiments of the
present invention, all or portions of the interior region formed by
housings 210, 220 may be filled with a material that is transparent
or substantially transparent to a wavelength of light emitted by
LEEs 140. In one embodiment of the present invention, the
transparent material includes or consists essentially of silicone,
polyurethane, epoxy, or other suitable materials. Examples of such
transparent materials include materials from the ASP series of
silicone phenyls manufactured by Shin Etsu, or the Sylgard series
manufactured by Dow Corning. In some embodiments of the present
invention, the transparent material may reduce
total-internal-reflection (TIR) losses of LEEs 140 and may provide
enhanced optical coupling between LEEs 140 and bottom housing 220.
In some embodiments of the present invention, the transparent
material has an index of refraction greater than about 1.4, or
greater than about 1.45.
In some embodiments of the present invention, a flexible membrane
or diaphragm may be disposed within a portion of a housing or
substrate 165 to accommodate expansion and contraction of the
atmosphere within the sealed region that may occur during storage
and/or operation, for example as a result of changes in temperature
or altitude. In some embodiments of the present invention, all or a
portion of a housing or substrate 165 has sufficient flexibility to
accommodate such expansions and contractions of the atmosphere
within the sealed region.
In some embodiments of the present invention, lighting device 200
may additionally include one or more optical elements to control
one or more optical characteristics, for example luminous or
radiant flux, CCT, CRI, R9, spectral power distribution,
light-distribution pattern, angular color uniformity, or the like.
In some embodiments, the optical elements may include an optic
substrate 264 having multiple optical elements 260 on one side of
optic substrate 264 and a second side (or "face") 267 opposite the
first side that is substantially flat and positioned in contact or
spaced apart from LEEs 140, as shown in FIG. 2B; however, this is
not a limitation of the present invention, and in other embodiments
rear face 267 may be shaped or patterned. For example, in some
embodiments of the present invention, rear face 267 of optic
substrate 264 may include indentations 261 into which fit one or
more LEEs 140, for example as shown in detail in FIG. 2C.
Optical elements 260 associated with optic substrate 264 may all be
the same or may be different from each other. Optical elements 260
may include or consist essentially of, e.g., a refractive optic, a
diffractive optic, a TIR optic, a Fresnel optic, or the like, or
combinations of different types of optical elements. Optical
elements 260 may be shaped or engineered to achieve a specific
light-distribution pattern from the array of light emitters,
phosphors and optical elements.
Optic substrate 264 typically features an array of optical elements
260; in some embodiments, one optical element 260 is associated
with each LEE 140, while in other embodiments multiple LEEs 140 are
associated with one optical element 260, or multiple optical
elements 260 are associated with a single LEE 140, or no engineered
optical element is associated with any LEEs 140, for example
portions of optic substrate 264 thereover may merely be flat or
roughened surfaces. In one embodiment, the optical elements 260
scatter, diffuse, and/or spread out light generated by LEEs
140.
FIG. 2B shows the axis of each optical element 260 as substantially
aligned with the center of an LEE 140; however, this is not a
limitation of the present invention, and in other embodiments
optical element 260 may be shifted in one or more lateral
directions with respect to an LEE 140, as detailed in U.S. Pat. No.
8,746,923, filed Dec. 4, 2012, the entire disclosure of which is
incorporated by reference. It should be noted that alignment, as
used herein, may mean that the center of one structure, for example
an LEE 140, is aligned with the center of another structure, for
example an optical element 260; however, this is not a limitation
of the present invention, and in other embodiments alignment refers
to a specified relationship between the geometries of multiple
structures.
Optical substrate 264 may be substantially optically transparent or
translucent. For example, optical substrate 264 may exhibit a
transmittance or reflectance greater than about 70% for optical
wavelengths ranging between about 400 nm and about 700 nm. Optical
substrate 264 may include or consist essentially of a material that
is transparent to a wavelength of light emitted by LEE 140, for
example having a transmittance greater than about 75%, or greater
than about 85% or greater than about 95% to a wavelength of light
emitted by LEE 140. Optical substrate 264 may be substantially
flexible or rigid. Optical elements 260 may be formed in or on
optical substrate 264. For example, optical elements 260 may be
formed by etching, polishing, grinding, machining, molding,
embossing, extruding, casting, or the like. The method of formation
of optical elements 260 is not a limitation of embodiments of the
present invention.
Optic substrate 264 may include or consist essentially of, for
example, acrylic, polycarbonate, polyethylene naphthalate (PEN),
polyethylene terephthalate (PET), polycarbonate, polyethersulfone,
polyester, polyimide, polyethylene, glass, or the like. In some
embodiments, optic substrate 264 includes or consists essentially
of multiple materials and/or layers.
The structure of FIGS. 2A and 2B shows the rear face 267 of optic
substrate 264 spaced apart from LEEs 140; however, this is not a
limitation of the present invention, and in other embodiments rear
face 267 of optic substrate 264 may be in contact with or
substantially in contact with LEEs 140. Space 263 (FIG. 2C) and
space 265 (FIG. 2B) between LEEs 140 and optic substrate 264 may be
evacuated to a relatively low pressure, or may be filled with air
or may be filled or partially filled with a material that is
transparent or substantially transparent to a wavelength of light
emitted by LEEs 140. In one embodiment of the present invention,
the transparent material includes or consists essentially of
silicone, epoxy or other suitable materials. Examples of such
transparent materials include materials from the ASP series of
silicone phenyls manufactured by Shin Etsu, or the Sylgard series
manufactured by Dow Corning. In some embodiments of the present
invention, the transparent material may reduce TIR losses in LEEs
140 and may provide enhanced optical coupling between LEEs 140 and
optic substrate 264. In some embodiments of the present invention,
the transparent material has an index of refraction greater than
about 1.4, or greater than about 1.45.
Substrate 165 may be affixed to optic substrate 264 by the
aforementioned transparent material or a similar material and/or by
other means, for example adhesive, glue, tape, mechanical
fasteners, or the like. In one embodiment of the present invention,
double-sided tape, such as 3M 467 MP, is used to affix substrate
165 to optic substrate 264. In one embodiment of the present
invention, a liquid adhesive, such as Dymax 3099, is used to affix
substrate 165 to optic substrate 264.
In some embodiments of the present invention, lighting device 200
may have lateral dimensions to fit or drop into standard-dimension
grid ceilings. For example, in North America some grid ceilings
have grid dimensions of about 2 feet by about 2 feet, or about 2
feet by about 4 feet. In some embodiments of the present invention,
lighting device 200 may have a height in the range of about 50 mm
to about 150 mm. In some embodiments of the present invention,
lighting device 100 may have a relatively light weight, for example
when housings 210, 220 include or consist essentially of ABS,
lighting device 200 may have a weight per area of less than about 5
kg/m.sup.2, or less than about 3 kg/m.sup.2 or less than about 1.5
kg/m.sup.2. In some embodiments of the present invention, lighting
device 200 having dimensions of about 60 cm by about 60 cm may
weigh less than about 1 kg, or less than about 0.7 kg. In some
embodiments of the present invention, lighting device 200 having
dimensions of about 60 cm by about 120 cm may weigh less than about
2 kg, or less than about 1.4 kg. It should be noted that the
weights described herein do not include a driver that drives LEEs
140. In some embodiments of the present invention, lighting device
200 may have a thickness less than about 70 mm or less than about
50 mm or less than about 30 mm, or less than about 15 mm or less
than about 10 mm, or less than about 5 mm, or less than about 3
mm.
Relatively lightweight lighting devices have several advantages.
First, they reduce the weight load on the building, potentially
permitting a reduction in new construction costs. Second, they are
easier to handle and install. In some embodiments of the present
invention, a lightweight lighting device may be installed, either
temporarily or permanently, using hook-and-loop fasteners,
adhesive, tape, dry wall hangers, nails, screws, or the like.
Third, shipping costs typically depend on size and weight. The
reduced weight of lighting devices of embodiments of the present
invention may thus reduce shipping costs. The relatively thin
profile of lighting devices of embodiments of the present invention
permits increased shipping density, for example more lighting
devices per shipping box or pallet, also resulting in lower
shipping and storage costs. In some embodiments, lighting devices
or ribbed lighting devices of embodiments of the present invention
may be designed to stack relatively tightly, with little need for
additional space or packing material for protection.
In some embodiments, bottom housing 220 may be eliminated and its
function replaced by optic substrate 264, as shown in FIG. 2D. In
some embodiments of the present invention, optical substrate 264
may be eliminated and its function replaced by a shaped bottom
housing 220. FIG. 2E shows one example of an embodiment of the
present invention in which bottom housing 220 is shaped to have
optical element shells 280, which in some embodiments correspond
functionally to optical elements 260 in FIG. 2B. In this
embodiment, region 281 between LEEs 140 and bottom housing 220 is
preferably filled or substantially filled with a material
transparent to a wavelength of light emitted by LEEs 140, as
described herein.
In some embodiments of the present invention bottom housing 220,
including optical shell elements 280, may be manufactured using a
thermoforming operation. Thermoforming or similar techniques permit
rapid, low cost, accurate formation of shaped plastic components,
resulting in a relatively low cost for lighting devices such as
lighting device 200.
In some embodiments of the present invention, the thickness of top
housing 210 may be in the range of about 0.1 mm to about 5 mm, or
in the range of about 0.3 mm to about 2.5 mm. In some embodiments
of the present invention, the thickness of housings 210, 220 are
substantially the same; however, in other embodiments, different
portions of housings 210, 220 may have different thicknesses. In
one embodiment of the present invention, the thickness of bottom
housing 220 in the region between optical shell elements 280,
identified as 282 in FIG. 2E, may be thinner than that of bottom
housing 220 in shell elements 280, permitting flexing or bending of
optic substrate 264 between optical shell elements 280. In this
embodiment, a lighting device may itself have a degree of
flexibility, permitting curving or bending of the entire lighting
device, as shown in FIG. 2F.
Lighting device 201, shown in FIG. 2F, includes substrate 165 on
which are formed LEEs 140 and that is mated to bottom housing 220.
In this embodiment of the present invention, top housing 210 is not
utilized; however, this is not a limitation of the present
invention, and in other embodiments top housing 210 may be included
in the structure of lighting device 201. While this example
incorporates bottom housing 210 having variable thickness, this is
not a limitation of the present invention, and in other embodiments
bottom housing 220 may have a substantially uniform thickness.
While the structure of FIG. 2F has been described as flexible, this
is not a limitation of the present invention, and in other
embodiments the structure of FIG. 2F may be rigid or substantially
rigid.
In another embodiment of the present invention, a portion of the
housing acts as a reflector for light emitted by LEEs 140. Lighting
device 300 of FIG. 3A includes LEEs 140 formed on substrate 165
which is mated to a housing 310. As shown, housing 310 incorporates
domes 320 or portions of the housing 310 have been shaped into
domes 320. (Conductive traces 160 are not shown in FIG. 3A for
clarity.) In some embodiments of the present invention, the
material of domes 320 and/or housing 310 are reflective to a
wavelength of light emitted by LEEs 140, while in other embodiments
all or a portion of housing 310 is coated with one or more coatings
that are reflective of a wavelength of light emitted by LEEs 140,
for example having a reflectance greater than about 75%, or about
85%, or about 95% to a wavelength of light emitted by LEEs 140. For
example, in one embodiment of the present invention, the interior
surface of dome 320 is coated with a reflective coating. In some
embodiments of the present invention, the reflective coating
includes or consists essentially of aluminum, copper, silver, gold,
chromium, or the like. In some embodiments of the present
invention, the reflective coating includes or consists essentially
of a reflective metal covered by one or more dielectric layers. In
some embodiments of the present invention, the reflective coating
is a dielectric mirror.
In these embodiments, substrate 165 is preferably transparent to a
wavelength of light emitted by LEEs 140, for example having a
transmittance of at least 75% or at least 85%, or at least 95%.
FIG. 3B shows a plan view of a portion of lighting device 300 of
FIG. 3A and shows conductive traces 160 that cover a portion of
substrate 165 under dome 320. In some embodiments, conductive
traces 160 are relatively thin, for example having a width 360 less
than about 1 mm or less than about 0.5 mm or less than about 0.25
mm. In some embodiments, width 360 is different (e.g., less) for
portions of conductive traces 160 disposed under dome 320, than it
is outside of dome 320. In some embodiments, the area of substrate
165 under dome 320 that is covered by conductive traces 160 is less
than 35% of total substrate 165 area under dome 320, or less than
25% of total substrate 165 area under dome 320, or less than 15% of
total substrate 165 area under dome 320, or less than 5% of total
substrate 165 area under dome 320, so as to minimize light loss as
light from LEE 140 is transmitted through substrate 165. In some
embodiments, conductive traces 160 may include or consist
essentially of a transparent conductor, for example indium tin
oxide (ITO), or other transparent conductive oxides (TCOs).
In some embodiments of the present invention, the shape of domes
320 may be engineered to produce different light-distribution
patterns. For example, in one embodiment of the present invention,
dome 320 has a substantially paraboloid shape and LEE 140 is
mounted substantially at the focal point of the paraboloid,
resulting in a relatively collimated beam 340 emitted from lighting
device 300. In another embodiment of the present invention, dome
320 may have a hemispherical shape, or may be a portion of a
hemisphere or paraboloid or may have any other shape. In some
embodiments, the region inside dome 320 may be evacuated, or filled
with air, or filled or partially filled with a material transparent
to a wavelength of light emitted by LEEs 140, as described
herein.
In another embodiment of the present invention, the housing element
facing LEEs 140 may be spaced apart from LEEs 140, for example as
shown in FIGS. 3C and 3D. In some embodiments of the present
invention, as shown in FIG. 3C, all or a portion of bottom housing
220 is transparent to a wavelength of light emitted by LEEs 140. In
some embodiments of the present invention, all or a portion of
bottom housing 220 is a diffuser and acts to diffuse or homogenize
the light emitted by individual LEEs 140, reducing or substantially
eliminating pixelization and producing a relatively or
substantially homogeneous plane of light, rather than a visible
array of individual points of illumination.
In the lighting device of FIG. 3C, bottom housing component 220 is
spaced apart from light sheet 110 by a spacing 370. In some
embodiments, spacing 370 is about 1.times. to about 3.times. a
spacing 125 between LEEs 140. In some embodiments, spacing 370 is
about 1.3.times. to about 2.times. the spacing 125. In some
embodiments, a total thickness of 371 of the lighting device is in
the range of about 5 mm to about 150 mm, or in the range of about
20 mm to about 100 mm.
In some embodiments of the present invention, as shown in FIG. 3D,
all or a portion of top housing 210 or a coating on the interior
surface of top housing 210 is reflective to a wavelength of light
emitted by LEEs 140, and all or a portion of substrate 165 is
transparent to a wavelength of light emitted by LEEs 140. Light 373
emitted by LEEs 140 is directed towards and reflected from top
housing 210 and exits the lighting device through light sheet 110.
In some embodiments of the present invention, a bottom housing may
be incorporated below substrate 165 (i.e., opposite top housing
210).
In some embodiments of the present invention, all or a portion of
bottom housing 220 is a diffuser and acts to diffuse or homogenize
the light emitted by individual LEEs 140, reducing or substantially
eliminating pixelization and producing a relatively or
substantially homogeneous plane of light. In some embodiments of
the present invention, top housing 210 or a coating on the interior
of top housing 210 may be a specular reflector, while in other
embodiments it may be a diffuse reflector. For example, in one
embodiment of the present invention, top housing 210 and/or a
coating on all or a portion of the interior surface of top housing
210 may be a diffuse reflector and have a reflectance greater than
about 90%, and substrate 165 may be transparent to a wavelength of
light emitted by LEEs 140. In some embodiments, the spectral
reflectance characteristics of top housing 210 or a coating on all
or a portion of the interior surface of top housing 210 may be
engineered to preferentially reflect or absorb one or more portions
of the spectral power distribution from LEEs 140, resulting in the
ability to modify one or more spectral characteristics of the
lighting device, for example CCT or CRI.
In some embodiments of the present invention, all or portions of
the structures of FIGS. 3C and 3D may be combined to produce
lighting devices similar to that shown in FIG. 3E. FIG. 3E shows a
lighting device in accordance with embodiments of the present
invention, including top housing 210 and bottom housing 220, both
of which are spaced apart from light sheet 110. As discussed
herein, all or a portion of top housing 210 may act as a specular
or diffuse reflector, while all or a portion of bottom housing 220
may be transparent or a diffuser. In this lighting device, light
emitted from LEEs 140 is directed substantially towards top housing
210, from which it is reflected and exits the lighting device after
transmitting through light sheet 110 and bottom housing 220. As
discussed herein, this structure reduces or substantially
eliminates pixelization and results in a relatively or
substantially homogeneous plane of light.
In some embodiments of the present invention, top housing 210 may
permit transmission of a portion of light emitted by LEEs 140 to
provide illumination in both upward and downward directions. For
example, in one embodiment of the present invention, the lighting
device may provide both direct and indirect illumination. In some
embodiments of the present invention, top housing 210 may include
or consist essentially of one or more portions having a relatively
high reflectance to a wavelength of light emitted by LEEs 140 and
one or more portions having a relatively high transmittance to a
wavelength of light emitted by LEEs 140. In one embodiment of the
present invention, top housing 210 may have substantially uniform
optical characteristics, for example having a transmittance to a
wavelength of light emitted by LEEs 140 in the range of about 20%
to about 70% and a reflectance to a wavelength of light emitted by
LEEs 140 in the range of about 20% to about 70%, with the
constraint that the reflectance and transmittance may not together
be greater than 100%.
The structures of FIGS. 2A-2F and 3A-3E may be manufactured in a
variety of ways. FIG. 4 shows a flow chart of a process 400 for
forming the structures of FIGS. 2A-2F and 3A-3E and similar
structures. Process 400 is shown having five steps; however, this
is not a limitation of the present invention, and in other
embodiments the invention has more or fewer steps and/or the steps
may be performed in different order. In step 410, a light sheet is
provided. In step 420, housing material is provided, e.g., as a
single piece or multiple pieces of material. In step 430, one or
more pieces of housing (i.e., housing components) are formed from
the housing material. In step 440, an electrical connector is
provided. In step 450, the housing component(s) and light sheet are
mated to form the lighting device. In some embodiments of the
present invention, the electrical connector is mated with the light
sheet in step 450; however, this is not a limitation of the present
invention, and in other embodiments the electrical connector may be
mated with the light sheet in a different step or in a separate
step.
FIGS. 5A-5E depict one embodiment of process 400. In this
embodiment, a light sheet 110 is provided in step 410, as shown in
FIG. 5A. The manufacture of the light sheet 110 includes provision
of a substrate 165, forming conductive traces 163 on the substrate
165, attaching and electrically coupling LEEs 140 and optionally
other components to the conductive traces 163 and the substrate
165. Additional details may be found herein and in the '807 and
'027 applications. However, the specific method of manufacture of
light sheet 110 is not a limitation of the present invention, and
in other embodiments other methods of manufacture of light sheet
110 may be utilized. For example, in some embodiments light sheet
110 may include or consist essentially of an interconnected array
of inorganic LEDs, while in other embodiments light sheet 110 may
include one or more organic light emitting diode (OLED)
elements.
In step 420 the housing material is provided. Depending on the
specific lighting device structure, this may be one piece of
housing material or multiple pieces of housing material. In some
embodiments, the material for all housing components is the same,
while in other embodiments different housing components may include
or consist essentially of different materials. For example, for the
device described in reference to FIG. 2A, material for the housing
components is provided, as shown in FIG. 5B. FIG. 5B shows two
types of material 510, 520 that will be used to manufacture top
housing 210 and bottom housing 220 respectively. In this example
material 520 is clear and has a transmittance to a wavelength of
light emitted by LEEs 140 greater than 95%, while material 510 is
white and has a reflectance to a wavelength of light emitted by
LEEs 140 greater than 95%.
In step 430 the housing components are formed. In some embodiments
of the present invention, forming may be cutting to a specific
shape, while in other embodiments this may include shaping the
material, for example to have a specific three-dimensional shape.
In other embodiments of the present invention, step 430 may include
applying one or more coatings to the materials provided in step
420. For example, for the device described in reference to FIG. 2A,
material 510 is cut to size and ribs are formed therewithin by
thermoforming to form top housing 210, while material 520 is cut to
size to form bottom housing 220, as shown in FIG. 5C. The method of
cutting, shaping, and/or coating of materials is not a limitation
of the present invention.
In step 440 one or more electrical connectors to the light sheet
are provided. In some embodiments of the present invention,
electrical connection includes providing power to light sheet 110,
for example to power conductors 120, 121, while in other
embodiments communication and/or control signals may also be
required to be coupled to light sheet 110. Electrical coupling to
the conductive traces or power conductors on light sheet 110 may be
accomplished in a variety of ways. In some embodiments of the
present invention, electrical coupling to the conductive traces may
be accomplished by attaching wires to the appropriate conductive
traces. In some embodiments, electrical coupling to the conductive
traces may be accomplished by a pressure connection.
In some embodiments of the present invention, electrical coupling
to the conductive traces may be accomplished by attaching one or
more wires 530 directly to a conductive element 540 (here
conductive element refers to any conductive trace or power
conductor on substrate 165), with solder or conductive adhesive or
anisotropic conductive adhesive (ACA) 532, as shown in FIG. 5D.
FIG. 5D shows wire 530 having optional insulation 534. In some
embodiments of the present invention, electrical coupling to the
conductive traces may be accomplished by attaching one or more
wires 530 to conductive element 540 by crimping, for example crimp
535 shown in FIG. 5E. Various crimp components may be used for this
purpose, for example Autosplice TC series or Nicomatic Crimplex
series crimp connectors; however, this is not a limitation of the
present invention, and in other embodiments other crimp elements
may be used.
In some embodiments of the present invention, electrical coupling
to the conductive traces may be accomplished by attaching one or
more connectors to the conductive traces, for example a Wago 2061
series connector or a Molex Lite-Trap series connector; however,
this is not a limitation of the present invention, and in other
embodiments other connectors may be used. FIG. 5F shows an example
of a connector 537 electrically coupled to conductive element 540,
for example using solder or conductive adhesive, and wire 530
inserted into connector 537. In some embodiments, wire 530 may have
a mating plug or component that mates to connector 537 (not shown
in FIG. 5F).
In some embodiments of the present invention, electrical connection
to conductive element 540 may be formed within the housing of the
lighting device and the wires attached to the light sheet may
extend outside of the housing. In some embodiments of the present
invention, a portion of one or more conductive elements may extend
beyond a portion of the housing, permitting access and electrical
coupling to the conductive traces outside of the housing, for
example as shown in FIG. 5G. FIG. 5G shows a portion of substrate
165 and conductive element 540 extending beyond the edge of bottom
housing 220, while being supported by top housing 210; however,
this is not a limitation of the present invention, and in other
embodiments substrate 165 and conductive element 540 may not be
supported or fully supported beyond the edge of the housing. In
some embodiments of the present invention, one or more wires may be
attached to the exposed portion of conductive element 540. In some
embodiments, one or more connectors may be formed on the exposed
portions of conductive element 540. In some embodiments of the
present invention, a portion of conductive element 540 and a
portion of underlying substrate 165 may be unsupported, i.e., not
backed by a portion of bottom housing 210, and this may be mated
with a connector, for example an edge connector or a
zero-insertion-force-type connector. In the embodiment of the
present invention shown in FIG. 5G, electrical connection to
conductive element 540 may be made using any of the methods
described herein, for example soldering, conductive adhesive,
crimping, ACA, or by other means.
In some embodiments of the present invention, housing 210, 220 may
be sealed over substrate 165 and conductive element 540. In some
embodiments, wires attached to conductive traces 160 are placed
between top housing 210 and bottom housing 220 before sealing, to
provide electrical access to light sheet 110. In some embodiments
of the present invention, the seal of housing 210, 220 over
substrate 165 and conductive element 540 or wire 530/534 may have
an IP rating between IP00 and IP69k. In some embodiments of the
present invention, the seal of housing 210, 220 over substrate 165
and conductive element 540 or wire 530/534 may have an IP 44
rating, an IP65 rating, an IP66 rating, an IP67 rating, or an IP 68
rating.
In some embodiments of the present invention, electrical connection
to conductive element 540 may be made using a pressure connection.
FIGS. 5H and 5I show examples of pressure connections; however,
other types of pressure connections may be utilized. FIG. 5H shows
clip 580 clamping wire 530 to conductive element 540. In FIG. 5I,
wire 530 is replaced by a rectangular or square cross-section
conductor 531, which is also held in place with clip 580. In some
embodiments of the present invention, clip 580 is spring-loaded,
while in other embodiments clip 580 includes a means for applying
pressure, for example a tightening screw or the like. In some
embodiments of the present invention, a conductive tape or
conductive glue or ACA or anisotropic conductive film (ACF) 582 may
be used to enhance electrical conductivity and robustness of the
pressure connection between wire 530 or 531 and conductive element
540, as shown in FIG. 5J. As discussed herein, such connections may
be made inside the housing or outside of the housing.
In step 450, the housing elements are mated with the light sheet
110 to form the lighting device. FIG. 5K shows top housing element
210, light sheet 110, and bottom housing element 220 positioned
before mating, and FIG. 5L shows the structure of FIG. 5K after
mating. Note that in this example, light sheet 110 extends beyond
the edge of top housing 210 and electrical connection to conductive
element 540 is made after step 450 in region 590, as described
herein.
In some embodiments of the present invention, top housing 210 and
bottom housing 220 may be joined by heat welding, high-frequency
welding, ultrasonic welding, laser welding, adhesive, glue, tape,
or the like. In some embodiments of the present invention, light
sheet 110 may be adhered to one or more portions of the housing,
for example, top housing element 210 or bottom housing element 220,
before mating. In some embodiments of the present invention, light
sheet 110 may be taped or glued to a portion of the housing before
mating.
In some embodiments of the present invention, the interior region
formed by housings 210, 220 may be purged and/or filled with an
inert gas, for example nitrogen or argon, prior to mating to reduce
the moisture and/or water vapor concentration and prevent
degradation or corrosion of light sheet 110 and associated
components.
In some embodiments of the present invention the interior region
formed by housings 210, 220 may be evacuated to a relatively low
pressure, or may be filled with air. In some embodiments of the
present invention, all or portions of the interior region formed by
housings 210, 220 may be filled with a material that is transparent
or substantially transparent to a wavelength of light emitted by
LEEs 140, as described herein. In some embodiments of the present
invention, the transparent material may also form the seal, for
example between housing 210, housing 220, and/or light sheet
110.
In some embodiments of the present invention, lighting devices may
be manufactured in sheets or rolls and cut to length. FIG. 6A shows
a plan view and FIGS. 6B-6D show cross-sectional views of lighting
devices manufactured according to various embodiments of the
present invention. The structure of FIG. 6B is similar to that of
FIG. 2F (without the curvature), while the structure of FIG. 6C is
similar to that of FIG. 2A, and the structure of FIG. 6D is similar
to that of FIG. 2E. Strings 150 are shown in FIGS. 6A-6D without
representation of the LEEs and interconnects, for clarity, and as
described herein, in some embodiments of the present invention,
light sheet 110 may be cut to length between strings 150. FIG. 6A
shows a plan view of a length of light sheet 110 including multiple
strings 150 and power conductors 120, 121 that may be cut to length
between strings 150, for example at a cut line 610. Cut line 610 is
also shown for the structures of FIGS. 6B-6D. In one embodiment of
the present invention, the required components, for example light
sheet 110 and the required housing element or elements, are mated
together before cutting. In some embodiments of the present
invention, the interior region of the housing is filled with a
transparent encapsulant or potting material, which itself provides
a seal, for example an IP44, IP65, IP66, IP67, or IP68 rated seal,
to the light sheet and housing elements. With such a seal, sheets
of lighting devices may be cut to length while still maintaining
their protected quality or rating, for example their IP rating.
In some embodiments, lighting devices of the present invention may
be manufactured in a roll-to-roll process. FIG. 7A shows one
embodiment of the present invention featuring a roll-to-roll
process for manufacture of lighting devices; however, this is not a
limitation of the present invention, and in other embodiments the
process has more or fewer steps and/or the steps may be performed
in different order. The exemplary manufacturing process shown in
FIG. 7A begins with three material feed streams, although this is
not a limitation of the present invention, and in other embodiments
fewer or more material feed streams may be utilized. A feed roll
710 supplies material 510 for top housing 210, a feed roll 720
supplies material 520 for bottom housing 220, and a feed roll 730
provides light sheet 110. Material 510 is optionally processed at a
processing station 715, for example to cut, shape, or coat material
510, as described herein, for example as described in relation to
FIGS. 5A-5L. Material 520 is optionally processed at a processing
station 725, for example to cut, shape, or coat material 520, for
example as described in reference to FIGS. 5A-5L. Formed material
510' and 520' are brought together with light sheet 110 at a mating
point 740 and sealed at a sealing station 750, for example as
described in reference to FIGS. 5A-5L, and cut to length at a
cutting station 755. Electrical contacts are formed at a wiring
station 760. The output of sealing station 750 is an essentially a
continuous lighting device 780, including light sheet 110 in a
housing. In the cutting station 755, the continuous lighting device
780 is cut into sections 785. In wiring station 760, electrical
contact is made to the light sheet, for example by a wire 790 being
electrically coupled to the light sheet 110.
While the process described with respect to FIG. 7 shows completed
light sheet 110 as being supplied on a roll, this is not a
limitation of the present invention, and in other embodiments
lights sheet 110 may itself be manufactured in a roll-to-roll
process that feeds into the system of FIG. 7, for example as shown
in FIG. 8. In FIG. 8, substrate 165 is supplied on a feed roll 810,
and LEEs 140 are mated to substrate 165 at a bonding station 820.
Light sheet 110 then feeds into the remainder of the process, as
described with reference to FIG. 7. In some embodiments of the
present invention, conductive elements 540, for example conductive
traces 160 and power conductors 120, 121, are pre-formed on
substrate 165 and supplied on feed roll 810. In other embodiments
of the present invention, conductive elements 540, for example
conductive traces 160 and power conductors 120, 121, are formed
in-line on substrate 165, for example before bonding station 820.
In some embodiments, conductive elements 540 may be formed using
screen printing, or lamination and etching or printing, for example
ink jet, gravure printing or the like. The method of forming
conductive elements 540 on substrate 165 is not a limitation of the
present invention.
While FIGS. 7 and 8 show the roll-to-roll process including a
singulation or cutting step, for example at cutting station 755 in
FIGS. 7 and 8, this is not a limitation of the present invention,
and in other embodiments the singulation step may be removed from
the roll-to-roll process, with the completed un-singulated
structure being rolled up stored on a take-up roll (not shown in
FIGS. 7 and 8).
In some embodiments, electrical contacts to light sheet 110 may be
formed as described in reference to FIG. 5G, where a portion of a
conductive element remains outside of the sealed housing. FIG. 9A
shows one embodiment of the present invention in cross-section,
looking perpendicularly into cut line 610 of FIG. 6B, in which
portions of power conductors 120, 121 are not covered by top
housing 210, permitting electrical access to power conductors 120,
121 after the housing is formed, for example as described in
reference to FIGS. 5H-5J and related text. In other embodiments of
the present invention, one or more wires or connectors may be
attached to the exposed portions of power conductors 120, 121
before or after the housing is sealed. In some embodiments of the
present invention, bottom housing 220 is optional.
FIG. 9B shows a plan view of the structure of FIG. 9A. The brackets
on the identifiers for substrate 165, bottom housing 220, power
conductors 120, 121 and top housing 210 indicate the width of these
elements. The cross-hatched portion of power conductors 120, 121,
identified as 120' and 121' in FIG. 9B, indicate the exposed
portions of power conductors 120, 121. In this example, portions of
power conductors 120, 121 are fully exposed along the full length
of the lighting device; however, this is not a limitation of the
present invention, and in other embodiments top housing may cover
additional regions of power conductors 120, 121 leaving
periodically spaced exposed portions of power conductors 120, 121
as shown in FIG. 9C. FIG. 9C shows a structure similar to that of
FIG. 9B; however, in the structure of FIG. 9C only portions of
power conductors 120, 121 are exposed periodically, not
continuously as in the structure of FIG. 9B. The brackets on the
identifiers for bottom housing 220 and top housing 210 indicate the
widths of these elements. In FIG. 9C, substrate 165 is not shown
for clarity. The exposed portions of power conductors 120, 121 are
identified as 120' and 121' in FIG. 9C.
In some embodiments of the present invention, electrical contacts
may be made by other techniques. For example, in some embodiments,
a crimp connection may be made through all or a portion of the
housing and a portion of substrate 165 and a portion of a
conductive element 540 before or after the housing is sealed. In
one embodiment of the present invention, the housing is sealed
without exposure of any conductive elements 540 and a crimp-type or
punch-type connection 915 is made through the housing, as shown in
FIG. 9D. The connection 915 may include or consist essentially of a
rivet or staple or other conductor piercing through the housing and
electrically contacting and/or piercing power conductor 120 and/or
substrate 165.
In some embodiments of the present invention, electrical contacts
may be formed before cutting or before sealing and cutting. Cutting
is then performed in such a way that each cut light sheet section
has the appropriate number and means of electrical connection, for
example the appropriate number of wires or connectors. In some
embodiments, the seal is performed over the wires.
FIG. 9E shows the structure of FIG. 6A at a later stage of
manufacture. In FIG. 9E, multiple wires 910, 910', 910'', and 911,
911', 911'' have been attached to power conductors 120 and 121
respectively, at points 920, 920', 920'' and points 921, 921',
921'', respectively. In this example, wire attachment points are
spaced apart on a power conductor (for example power conductor 120,
121) by about four strings 150.
FIG. 9F shows the structure of FIG. 9E at a later stage of
manufacture. In FIG. 9F, light sheet 110 has been mated and sealed
into housing 930 and cut to lengths corresponding to the spacing of
the wire attachment points 920 and 920' and 921 and 921', forming
lighting devices 900 and 900', each of which has four strings 150
and wires 910 and 911 and wires 910' and 911' electrically coupled
to power conductors 120 and 121 respectively. In FIG. 9F, the
portions of the structure of FIG. 9E corresponding to wires 910''
and 911'' are not shown for clarity.
In some embodiments of the present invention, the electrical
connection has the same protection rating, for example IP rating,
as the housing, resulting in a system having the desired rating,
for example IP 65, IP 66, IP 67, or IP 68.
As discussed herein, other components may be formed on substrate
165 to provide additional functionality to the lighting devices,
for example sensors, such as occupancy sensors, light sensors such
as light intensity sensors, humidity sensors, fire and/or smoke
sensors, communication systems, or the like.
While the process described with respect to FIGS. 9E and 9F results
in the manufacture of multiple luminaires having substantially the
same size and properties, this is not a limitation of the present
invention, and in other embodiments lighting devices having
different lengths, or different numbers of strings, may be
manufactured on the same production line by varying the spacing
between wire attachment and cutting. In some embodiments of the
manufacturing process of the present invention, the type of LEEs
140 formed on substrate 165 may vary. For example, a continuous
process may be operated in which light sheet 110 having a first
type of LEE is manufactured for a given time or length and then the
first type of LEE may be replaced with a second type of LEE,
without stopping or significantly slowing down the manufacturing
operation. In one embodiment of the present invention, this may be
accomplished in the system of FIG. 7 by replacing or splicing a
second type of light sheet including the second type of LEE onto
the material in feel roll 730 or by using a light sheet having
different types of LEEs formed in different regions. In some
embodiments, this may be done without stopping or significantly
slowing down the roll-to-roll process. In some embodiments of the
present invention, this may be accomplished in the system of FIG. 8
by replacing the first type of LEE with a second type of LEE at
bonding station 820 in FIG. 8. For example, different types of LEEs
may have a different CCT, CRI, luminous flux, R9, angular color
uniformity or the like.
In some embodiments of the present invention, CE 145 or one or more
components making up CE 145 may be changed in the manufacturing
process without stopping or significantly slowing down the
roll-to-roll process, in a similar fashion as that described herein
for changing the type of LEE. For example, feed roll 730 in FIG. 7
may include light sheet 110 with different portions, each portion
having a different CE 145 or one or more different components
making up CE 145 or a second light sheet 110 having a different CE
145 or one or more different components making up CE 145 may be
spliced onto feed roll 730. In some embodiments of the present
invention, CE 145 or the components making up CE 145 may be formed
on substrate 165 in bonding station 820 of FIG. 8. In some
embodiments of the present invention, the type of CE 145 or one or
more components of CE 145 making up CE 145 may be changed during
the manufacturing process, without stopping or significantly
slowing down the roll-to-roll manufacturing process. In some
embodiments of the present invention, the pattern of conductive
elements on substrate 165 may be varied during the manufacturing
process, for example in the system of FIG. 8, substrate 165 is
supplied to bonding station 820 and within bonding station 820, the
conductive elements may be formed on substrate 165 as well as LEEs
140 and CEs 145.
Such embodiments of the invention result in the ability to
manufacture large volumes of lighting devices in a roll-to-roll
process with a standardized product, with a semi-custom product or
with a fully customized product. For example, customization may
include different LEEs 140 having different properties, different
conductive trace patterns, different pitch or patterns between
LEEs, different drive currents for LEEs 140, or different types of
material for the housing. For example, housing elements 210, 220
may include or consist essentially of different materials, for
example a transparent housing element and a diffusing housing
element, or a different thickness material for the housing.
Customization may also include options for different substrate
materials, for example transparent or opaque to a wavelength of
light emitted by LEEs 140, or different thickness substrate,
different additional elements such as sensors, communication
devices, or the like. In an automated system, in one embodiment of
the present invention, the desired quantity and parts are
programmed into the system, which then manufactures, in a
continuous process, a wide range of differentiated or customized
lighting devices having different electrical, optical or physical
characteristics.
In another embodiment of the present invention, lighting devices
may be manufactured entirely or in part by lamination. For example,
the housing may be fabricated by lamination, as when a top housing
210 is formed over LEEs 140 and an optional bottom housing 220 by
lamination. In the lamination process, a layer is formed and
adhered to light sheet 140 over LEEs 140, providing for example
mechanical protection and/or electrical protection (covering
conductive traces and other electrically active elements), water
and/or moisture protection for example to achieve an IP rating,
dust protection, and the like.
In some embodiments, the layer of film to be laminated is adhered
to the light sheet using a liquid adhesive that is applied to the
light sheet or the film or both before mating, or a dry adhesive
that is applied to the film or light sheet or both before mating.
In some embodiments, lamination may be performed on a sheet basis,
while in other embodiments lamination may be performed using a
roll-to-roll process.
FIG. 10A shows one embodiment of the present invention that
utilizes a pouch lamination process; however, other embodiments may
have more or fewer steps and/or the steps may be performed in a
different order. Light sheet 110 is inserted into an opening 1040
of a pouch 1030, which includes a top pouch layer 1010 and a bottom
pouch layer 1020. Adhesive is disposed on portions or all of the
interior surface of pouch 1030. Pressure and/or heat is then
applied to the structure of FIG. 10A, resulting in the laminated
structure of FIG. 10B. In another embodiment of the present
invention, only a top lamination layer, for example top pouch layer
1010, is used, and substrate 165 forms the back of the laminated
structure, as shown in FIG. 10C.
In some embodiments of the present invention, lamination is
performed in a roll-to-roll process, for example as shown in FIG.
10D. FIG. 10D shows a feeder roll 1011 for top lamination film
1010, a feeder roll 1021 for optional bottom lamination film 1020,
a feeder roll 1015 for light sheet 110, and a lamination stage
1040. Light sheet 110 is mated with top lamination film 1010 and
optionally bottom lamination film 1020 at lamination stage 1040,
producing the final structure 1050. In some embodiments of the
present invention, laminated light sheet 1050 is cut into sheets
after lamination stage 1040, while in other embodiments laminated
light sheet 1050 is rolled up onto a take-up roll 1070. In some
embodiments of the present invention, lamination stage 1040 is a
cold lamination process, in which lamination occurs substantially
through the application of pressure. In some embodiments of the
present invention, lamination stage 1040 is a hot lamination
process, in which lamination occurs through the application of both
heat and pressure. Some embodiments of the present invention may
utilize a lamination tape, which is laminated on light sheet 110
substantially through the application of pressure.
In some embodiments, the lamination film may include or consist
essentially of a semicrystalline or amorphous material, e.g.,
polyethylene naphthalate (PEN), polyethylene terephthalate (PET),
polycarbonate, polyethersulfone, polyester, polyimide,
polyethylene, or the like. In some embodiments, the lamination film
is the same material as substrate 165, while in other embodiments
the lamination film is a different material. In preferred
embodiments of the present invention, the lamination film is
transparent to a wavelength of light emitted by LEEs 140, for
example having a transmittance greater than about 75% or greater
than about 85% or greater than about 95% to such light.
In some embodiments of the present invention, variations in the
roll-to-roll lamination manufacturing process may be the same as or
similar to those described herein with respect to other
roll-to-roll manufacturing processes, for example with reference to
FIGS. 8 and 9. In some embodiments of the present invention,
methods of making electrical contact to a laminated light sheet may
be similar to or the same as described herein with respect to other
configurations of the present invention.
In some embodiments of the present invention, the housing may be
formed via a coating process. In some embodiments, a coating may be
a conformal or substantially conformal coating, while in other
embodiments the coating may not be conformal. In some embodiments,
a coating may include or consist of one layer, while in other
embodiments a coating may include or consist essentially of more
than one layer. In some embodiments of the present invention, a
multi-layer coating may include or consist essentially of multiple
layers of the same material, while in other embodiments a
multi-layer coating may include or consist essentially of different
materials. In some embodiments of the present invention, multiple
layers may be used to ensure integrity of the coating material, for
example to reduce the occurrence of or eliminate pinholes or other
defects that may compromise the integrity of the coating.
FIG. 11A shows one embodiment of the present invention that
utilizes a coating process; however, other embodiments may have
more or fewer steps and/or the steps may be performed in a
different order. FIG. 11A shows one embodiment of the present
invention for manufacture of a coated light sheet; however, in
other embodiments, the number of steps in the process may be
greater or fewer and the steps may be performed in a different
order. In the process of FIG. 11A, light sheet 110 is supplied on a
feed roll 1165. Light sheet 110 is passed through a coating bath
1110 containing coating material 1120 (typically in liquid form),
resulting in a coated material 1130 that is then cured at a curing
stage 1130, resulting in a coated light sheet 1140 that is stored
on a take-up roll 1166. In some embodiments, coating stage 1130
includes or consists essentially of a thermal cure; however, this
is not a limitation of the present invention, and in other
embodiments other curing methods may be used, for example UV cure,
radiation cure, room temperature cure, moisture-induced curing, or
the like. While FIG. 11A shows a roll-to-roll coating process, this
is not a limitation of the present invention, and in other
embodiments coating may be performed on a sheet-by-sheet basis.
While FIG. 11A shows a dip coating process, this is not a
limitation of the present invention, and in other embodiments the
coating material may be applied by other techniques, for example
spraying, brushing, doctor blade, or printing (e.g., screen,
gravure or other printing methods).
FIG. 11B shows an example of coated light sheet 1140 with a
conformal or substantially conformal coating 1180, while FIG. 11C
shows an example of coated light sheet 1140 with a non-conformal
coating 1180. In some embodiments of the present invention, coating
1180 is applied to the front side of light sheet 110 but not the
opposite side of light sheet 110, as shown in FIG. 11D.
In some embodiments of the present invention, variations in the
coating manufacturing process may be the same as or similar to
those described herein with respect to other roll-to-roll
manufacturing processes, for example with reference to FIGS. 8 and
9. In some embodiments of the present invention, methods of making
electrical contact to coated light sheet may be the same as or
similar to those described herein with respect to other
configurations of the present invention.
In some embodiments of the present invention, the housing or
coating or lamination material is sealed to light sheet 110, for
example to the substrate 165 between LEEs 140, such that cutting
light sheet 110 between LEEs 140 retains the integrity of the
protection (i.e., does not expose individual LEEs 140 to the
outside ambient). For example, in some embodiments of the present
invention, the completed structure, including the covering
material, for example a housing, a coating, a lamination or the
like, may have an IP 44 rating or higher, for example IP65, IP 66,
IP67, IP 68 or the like both before and after cutting of the
structure between LEEs 140 to form two or more completed
structures.
While lighting devices of the present invention have been described
with reference to use in grid or T-grid ceiling systems, this is
not a limitation of the present invention, and in other embodiments
lighting devices of the present invention may be mounted in other
configurations, for example flush mounted to a surface such as a
ceiling or a wall, suspended from one or more cables, mounted on a
pole, or the like.
In some embodiments of the present invention, all or portions of
polymeric bottom housing 220 and/or polymeric top housing 210
and/or substrate 165 may have decorations or designs attached to
them or printed on them. In some embodiments of the present
invention, all or portions of polymeric bottom housing 220 and/or
polymeric top housing 210 and/or substrate 165 may be colored.
FIG. 12A shows one embodiment of the present invention that
features a lighting device 1210 and a driver or power supply 1220.
Driver 1220 is powered by, e.g., an AC mains 1230, for example
having a voltage of about 120 VAC or a voltage of about 240 VAC or
about 277 VAC; however, the value of the voltage and/or its time
dependence (i.e., AC or DC or another arbitrary waveform) are not
limitations of the present invention. In some embodiments of the
present invention, driver 1220 is a substantially constant voltage
supply. In some embodiments of the present invention, the output of
driver 1220 is pulse-width modulated to enable dimming of LEEs 140.
In some embodiments, driver 1220 has a UL class 2 rating, having a
voltage output not exceeding 60V. In some embodiments of the
present invention, driver 1220 may include a battery backup system,
to provide power to lighting system 1210 in case of a failure of
main power 1230.
In some embodiments of the present invention, driver 1220 is
located outside of lighting device 1210, where, for example,
lighting device 1210 is similar to the lighting devices shown in
FIG. 2A, 2B, 2E, 2F, or the like. In some embodiments, one driver
1220 may power one lighting device 1210, as shown in FIG. 12A,
while in other embodiments one driver 1220 may power more than one
lighting device 1210, as shown in FIG. 12B. FIG. 12B shows one
embodiment of the present invention that features three lighting
devices 1210, with two connected electrically in series and one
connected electrically in parallel to the series-connected lighting
device 1210; however, this is not a limitation of the present
invention, and in other embodiments all lighting devices may be
connected in series, or all lighting devices may be connected in
parallel or they may be connected in any other configuration. While
FIG. 12B shows three lighting devices 1210, this is not a
limitation of the present invention, and in other embodiments fewer
or more lighting devices 110 may be utilized. FIG. 12B shows three
lighting devices 1210 that are substantially the same; however,
this is not a limitation of the present invention, and in other
embodiments driver 1220 may provide power to different types of
lighting devices 1210, for example having different sizes,
different numbers of LEEs 140 or different spectral or optical
characteristics. In some embodiments, driver 1220 may be
incorporated in the housing of the lighting device 1210, as shown
in FIG. 12C.
In some embodiments, control and/or communication signals, either
to or from the lighting system, or in two-way communication with
the lighting system, may also be enabled in embodiments of the
present invention. For example, such signals may include a dimming
signal, signals providing sensor output (e.g., from a sensor such
as a light sensor, occupancy sensor or the like), connection to a
lighting control system (e.g., DALI, DMX or the like), or a
facilities management system, a safety system, or the like. In some
embodiments of the present invention, such sensors may be
incorporated within driver 1220, or within lighting device 1210 or
on light sheet 110, while in other embodiments such sensors may be
incorporated externally to lighting device 1210 and driver
1220.
In some embodiments of the present invention, such signals may
provide control information to the lighting system, for example to
energize it, to de-energize it, to change the light level (e.g.,
dimming), to change the CCT, to change the spectral power density,
to change the luminous intensity distribution or the like. In some
embodiments of the present invention, such signals may provide
information about the lighting system, for example a defect or
failure in lighting device 1210 and/or driver 1220, the temperature
of lighting device 1210 and/or driver 1220, the location of
lighting device 1210 and/or driver 1220, the optical
characteristics of lighting device 1210 or the like.
In some embodiments of the present invention, one or more control
and/or communication signals may be transmitted to driver 1220,
while in other embodiments one or more control and/or communication
signals may be transmitted to lighting device 1210, or in other
embodiments one or more control and/or communication signals 1240
may be transmitted to both driver 1220 and lighting device 1210, as
shown in FIG. 12D. In some embodiments of the present invention,
such control and/or communication signals may be transmitted to
lighting device 1210 and/or driver 1220 wirelessly, for example
using light-based communication such as infra-red (IR) or
ultra-violet (UV) or visible light, radio-based communication, for
example WIFI, Bluetooth or the like. The method and/or protocol of
control and communication signal transmission to driver 1220 and/or
lighting device 1210 is not a limitation of the present
invention.
In some embodiments, warning or other annunciation signals may be
displayed by lighting device 1210. In some embodiments of the
present invention, light sheet 110 or portions of light sheet 110
or lighting device 1210 may be energized and de-energized to
provide a blinking indication. In some embodiments of the present
invention, light sheet 110 may be cut or formed into one or more
shapes, symbols or letters, to provide additional information or
indications. For example light sheet 110 may be shaped into an
arrow, a stop sign, a cross, or other shapes. In some embodiments
of the present invention, LEEs 140 on light sheet 110 may be
positioned to form one or more shapes, symbols or letters, for
example an arrow, a "DO NOT ENTER" sign, a no smoking symbol, a no
entry symbol, a symbol for fire, or the like.
As utilized herein, the term "light-emitting element" (LEE) refers
to any device that emits electromagnetic radiation within a
wavelength regime of interest, for example, visible, infrared or
ultraviolet regime, when activated, by applying a potential
difference across the device or passing a current through the
device. Examples of light-emitting elements include solid-state,
organic, polymer, phosphor-coated or high-flux LEDs, laser diodes
or other similar devices as would be readily understood. The
emitted radiation of an LEE may be visible, such as red, blue or
green, or invisible, such as infrared or ultraviolet. An LEE may
produce radiation of a continuous or discontinuous spread of
wavelengths. An LEE may feature a phosphorescent or fluorescent
material, also known as a light-conversion material, for converting
a portion of its emissions from one set of wavelengths to another.
In some embodiments, the light from an LEE includes or consists
essentially of a combination of light directly emitted by the LEE
and light emitted by an adjacent or surrounding light-conversion
material. An LEE may include multiple LEEs, each emitting
essentially the same or different wavelengths. In some embodiments,
a LEE is an LED that may feature a reflector over all or a portion
of its surface upon which electrical contacts are positioned. The
reflector may also be formed over all or a portion of the contacts
themselves. In some embodiments, the contacts are themselves
reflective. Herein "reflective" is defined as having a reflectivity
greater than 65% for a wavelength of light emitted by the LEE on
which the contacts are disposed. In some embodiments, an LEE may
include or consist essentially of an electronic device or circuit
or a passive device or circuit. In some embodiments, an LEE
includes or consists essentially of multiple devices, for example
an LED and a Zener diode for static-electricity protection. In some
embodiments, an LEE may include or consist essentially of a
packaged LED, i.e., a bare LED die encased or partially encased in
a package. In some embodiments, the packaged LED may also include a
light-conversion material. In some embodiments, the light from the
LEE may include or consist essentially of light emitted only by the
light-conversion material, while in other embodiments the light
from the LEE may include or consist essentially of a combination of
light emitted from an LED and from the light-conversion material.
In some embodiments, the light from the LEE may include or consist
essentially of light emitted only by an LED.
One or more non-LEE devices such as Zener diodes, transient voltage
suppressors (TVSs), varistors, etc., may be placed on each light
sheet to protect the LEEs 140 from damage that may be caused by
high-voltage events, such as electrostatic discharge (ESD) or
lightning strikes. In one embodiment, conductive trace segments
shown in FIG. 1B or 1C between the LEE strings 150 may be used for
placement of a single protection device per light sheet, where the
device spans the positive and negative power traces, for example
power conductors 120,121. These trace segments also serve to
provide a uniform visual pattern of lines in the web direction,
which may be more aesthetically pleasing than a light sheet with
noticeable gaps between LEE strings 150. In a more general sense,
in addition to conductive traces 160 that are part of string 150,
additional conductive traces 160 that may or may not be
electrically coupled to other strings 150 and/or power conductors
120,121 may be formed on substrate 165, for example to provide
additional power conduction pathways or to achieve a decorative or
aesthetically pleasing look to the pattern on the light sheet or to
provide a communication pathway to one or more CEs 145, for example
to provide a control signal to the one or more CEs 145. These trace
segments also serve to provide a uniform visual pattern of lines in
the web direction, which may be more aesthetically pleasing than a
light sheet with noticeable gaps between LEE strings 150.
In one embodiment, an LEE 140 includes or consists essentially of a
bare semiconductor die, while in other embodiments LEE 140 includes
or consists essentially of a packaged LED.
In some embodiments, an LEE 140 may include or consist essentially
of a "white die" that includes an LED that is integrated with a
light-conversion material (e.g., a phosphor) before being attached
to the light sheet, as described in U.S. patent application Ser.
No. 13/748,864, filed Jan. 24, 2013, or U.S. patent application
Ser. No. 13/949,543, filed Jul. 24, 2013, the entire disclosure of
each of which is incorporated by reference herein.
In some embodiments, LEEs 140 may emit light in a relatively small
wavelength range, for example having a full width at half maximum
in the range of about 20 nm to about 200 nm. In some embodiments,
all LEEs 140 may emit light of the same or substantially the same
wavelength, while in other embodiments different LEEs 140 may emit
light of different wavelengths. In some embodiments, LEEs 140 may
emit white light, for example that is perceived as white light by
the eye. In some embodiments, the white light may be visible light
with a spectral power distribution the chromaticity of which is
close to the blackbody locus in the CIE 1931 xy or similar color
space. In some embodiments, white light has a color temperature in
the range of about 2000 K to about 10,000 K. The emission
wavelength, full width at half maximum (FWHM) of the emitted light
or radiation or other optical characteristics of LEEs 140 may not
be all the same and are not a limitation of the present
invention.
Advantageously, embodiments of the present invention produce a
light sheet 110 having controlled optical characteristics. In some
embodiments of the present invention it is advantageous to have
multiple light sheets, each of which as a similar CCT, preferably
the average CCT of each light sheet during manufacture or use
having a relatively narrow CCT distribution. One measure of white
color temperature is defined as a MacAdam ellipse. A MacAdam
ellipse represents a region of colors on a chromaticity chart, for
example the CIE chromaticity diagram, and a one-step MacAdam
ellipse represents the range of colors around the center of the
ellipse that are indistinguishable to the average human eye, from
the color at the center of the ellipse. The contour of a one-step
MacAdam ellipse therefore represents barely noticeable differences
of chromaticity.
Multiple-step MacAdam ellipses may be constructed that encompass
larger ranges of color around the center point. While there are
many recommendations as to how tight the color temperature
uniformity should be (as measured by MacAdam ellipses or other
units), a variation encompassed within a smaller step number of
MacAdam ellipses (smaller ellipse) is more uniform than one
encompassed within a larger step number of MacAdam ellipses (larger
ellipse). For example, a four-step MacAdam ellipse encompasses
about a 300K color temperature variation along the black body
locus, centered at 3200K, while a two-step MacAdam ellipse
encompasses about a 150K color temperature variation along the
black body locus, centered at 3200K.
In some embodiments of the present invention, the variation in
average CCT between different light sheets 110 is less than 4
MacAdam ellipses, or less than 3 MacAdam ellipses or less than 2
MacAdam ellipses.
Substrate 165 may include or consist essentially of a
semicrystalline or amorphous material, e.g., polyethylene
naphthalate (PEN), polyethylene terephthalate (PET), polycarbonate,
polyethersulfone, polyester, polyimide, polyethylene, fiberglass,
FR4, metal core printed circuit board, (MCPCB), and/or paper.
Substrate 165 may include multiple layers, for example, a
semicrystalline or amorphous material, e.g., PEN, PET,
polycarbonate, polyethersulfone, polyester, polyimide,
polyethylene, and/or paper formed over a second substrate for
example comprising, acrylic, aluminum, steel and the like.
Depending upon the desired application for which embodiments of the
invention are utilized, substrate 165 may be substantially
optically transparent, translucent, or opaque. For example,
substrate 165 may exhibit a transmittance or a reflectivity greater
than 70% for optical wavelengths ranging between approximately 400
nm and approximately 700 nm. In some embodiments substrate 165 may
exhibit a transmittance or a reflectivity of greater than 70% for
one or more wavelengths emitted by LEEs 140. Substrate 165 may also
be substantially insulating, and may have an electrical resistivity
greater than approximately 100 ohm-cm, greater than approximately
1.times.10.sup.6 ohm-cm, or even greater than approximately
1.times.10.sup.10 ohm-cm. In some embodiments, substrate 165 may
have a thickness in the range of about 10 .mu.m to about 500
.mu.m.
Conductive elements, e.g., power conductors 120, 121 and conductive
traces 160, may be formed via conventional deposition,
photolithography, and etching processes, plating processes,
lamination, lamination and patterning, evaporation sputtering or
the like or may be formed using a variety of different printing
processes. For example, power conductors 120, 121 and conductive
traces 160 may be formed via screen printing, flexographic
printing, ink-jet printing, and/or gravure printing. Power
conductors 120, 121 and conductive traces 160 may include or
consist essentially of a conductive material (e.g., an ink or a
metal, metal film or other conductive materials or the like), which
may include one or more elements such as silver, gold, aluminum,
chromium, copper, and/or carbon. Power conductors 120, 121 and
conductive traces 160 may have a thickness in the range of about 50
nm to about 1000 .mu.m. In some embodiments, the thickness of power
conductors 120, 121 and conductive traces 160 may be determined by
the current to be carried thereby. While the thickness of one or
more of power conductors 120, 121 and conductive traces 160 may
vary, the thickness is generally substantially uniform along the
length of the trace to simplify processing. However, this is not a
limitation of the present invention, and in other embodiments the
thickness and/or material of power conductors 120, 121 and
conductive traces 160 may vary. In some embodiments, all or a
portion of power conductors 120, 121 and conductive traces 160 may
be covered or encapsulated. In some embodiments, a layer of
material, for example insulating material, may be formed over all
or a portion of power conductors 120, 121 and conductive traces
160. Such a material may include, e.g., a sheet of material such as
used for substrate 165, a printed layer, for example using screen,
ink jet, stencil or other printing means, a laminated layer, or the
like. Such a printed layer may include, for example, an ink, a
plastic and oxide, or the like. The covering material and/or the
method by which it is applied is not a limitation of the present
invention.
In some embodiments of the present invention, all or a portion of
substrate 165 and/or power conductors 120, 121 and conductive
traces 160 may be covered by a layer having pre-determined optical
properties. In some embodiments, the optical properties of
substrate 165 or a coating material on substrate 165, for example
reflectance, transmittance and absorption, may be utilized to
further control the optical characteristics of the lighting system.
In some embodiments, substrate 165 or a coating on substrate 165
may be a diffuse reflector, while in other embodiments it may be a
specular reflector, and in yet other embodiments it may be designed
to have a relatively high absorbance for light emitted by LEEs 140.
In some embodiments of the present invention, substrate 165 may
have a reflectance of at least 80% or at least 90% or at least 95%
to a wavelength of light emitted by LEEs 140. In some embodiments
of the present invention, substrate 165 may be transparent or
substantially transparent to a wavelength of light emitted by LEEs
140, for example having a transmittance of at least 80% or at least
90% or at least 95% to a wavelength of light emitted by LEEs 140.
In some embodiments of the present invention, substrate 165 may be
absorbing or substantially absorbing to a wavelength of light
emitted by LEEs 140, for example having an absorbance of at least
60% or at least 70% or at least 80% to a wavelength of light
emitted by LEEs 140. In some embodiments, substrate 165 or portions
of substrate 165 may be configured to diffuse a wavelength of light
emitted by LEEs 140. In some embodiments, substrate 165 may have
two or more regions, where different regions have different optical
characteristics. In some embodiments, the transmittance of a
diffuse region is at least 50%, or at least 70% or at least 80%, or
at least 90% to a wavelength of light emitted by LEEs 140. The
remaining portion of substrate 165 in some embodiments has a
reflecting surface, i.e., it is reflecting to a wavelength of light
emitted by LEEs 140.
In one embodiment, conductive traces 160 are formed with a gap
between adjacent conductive traces 160, and LEEs 140 and CEs 145
are electrically coupled to conductive traces 160 using conductive
adhesive, e.g., an isotropically conductive adhesive and/or an ACA,
as described in U.S. Pat. No. 8,384,121, filed on Jun. 29, 2011,
the entire disclosure of which is incorporated herein by reference.
ACAs may be utilized with or without stud bumps and embodiments of
the present invention are not limited by the particular mode of
operation of the ACA. For example, the ACA may utilize a magnetic
field rather than pressure (e.g., the ZTACH ACA available from
SunRay Scientific of Mt. Laurel, N.J., for which a magnetic field
is applied during curing in order to align magnetic conductive
particles to form electrically conductive "columns" in the desired
conduction direction). Furthermore, various embodiments utilize one
or more other electrically conductive adhesives, e.g.,
isotropically conductive adhesives, non-conductive adhesives, in
addition to or instead of one or more ACAs. In other embodiments,
LEEs 140 and CEs 145 may be attached to and/or electrically coupled
to conductive traces 160 by other means, for example solder, reflow
solder, wave solder, wire bonding, or the like. The method by which
LEEs 140 and CEs 145 are attached to conductive traces 160 is not a
limitation of the present invention.
CE 145 may be one component or multiple active and/or passive
components. In one embodiment, power conductors 120,121 provide a
DC voltage or substantially DC voltage and CE 145 includes or
consists essentially of a resistor, e.g. a current-limiting
resistor. The choice of the resistance value may be a trade-off
between a number of parameters and characteristics that may
include, e.g., efficiency and current stability. In general, a
larger resistance will result in reduced efficiency but greater
current stability, while a smaller resistance will result in
increased efficiency but reduced current stability. Variations in
the current may result from variations in the input voltage (for
example across power conductors 120, 121), variations in forward
voltage of the LEEs 140 within the string, variations in the value
of the current-limiting resistor, variations in current that may
occur if one or more LEEs 140 in the string become short-circuited
or the like. In the case of CE 145 including or consisting
essentially of a resistor, in some embodiments CE 145 is a discrete
resistor formed within or on conductive traces 160, such as a chip
resistor, a bare-die resistor or surface mount device (SMD)
resistor.
As discussed above, in embodiments where CE 145 includes or
consists essentially of a resistor, there may be trade-offs between
efficiency and current stability. While such trade-offs may be
acceptable in certain products, other products may require
relatively better current stability at higher efficiencies, and in
these cases CE 145 may include or consist essentially of multiple
components or a circuit element, as discussed above. In some
embodiments CE 145 includes or consists essentially of a
field-effect transistor (FET) and a resistor. In another embodiment
CE 145 includes or consists essentially of two bipolar junction
transistors (BJTs) and two resistors.
In some embodiments, the efficiency and current stability increase
with the number of components, as does the cost. In some
embodiments where CE 145 includes or consists essentially of
multiple components, the components may be in discrete form (i.e.,
each component individually electrically coupled to conductive
traces 160) or in hybrid form (where multiple separate components
are mounted on a submount, which is then electrically coupled to
conductive traces 160), or in monolithic form (where multiple
components are integrated on a semiconductor chip, for example a
silicon-based or other semiconductor-based integrated circuit). In
some embodiments, CE 145 may be in bare-die form, while in other
embodiments CE 145 may be packaged or potted or the like. In some
embodiments, CE 145 may include or consist essentially of a
bare-die integrated circuit. In some embodiments, the integrated
circuit includes or consists essentially of multiple active and/or
passive devices that are fabricated on a common semiconductor
substrate.
In other embodiments, power conductors 120, 121 may provide AC
power, or power modulated at different frequencies and in these
embodiments CEs 145 may be selected accordingly or may be omitted.
In one embodiment, power conductors 120, 121 may provide a standard
line voltage, for example about 120 VAC or about 240 VAC or about
277 VAC, for example at about 50 Hz or about 60 Hz. In some
embodiments, CEs 145 may accommodate a plurality of input types,
and thus be so-called "universal" CEs 145, while in other
embodiments different CEs 145 may be required for different input
types. The actual component or components of CEs 145 are not
limiting to this invention; however, in preferred embodiments of
this invention, the positioning of CEs 145 does not disrupt the LEE
pitch. In another embodiment of this invention, the positioning of
CEs 145 is independent of LEE pitch. As discussed herein, CEs 145
and LEEs 140 may be electrically coupled to conductive traces 160
using a variety of means, for example solder, conductive adhesive
or anisotropic conductive adhesive (ACA); however, the method of
electrical coupling of CEs 145 and LEEs 140 is not a limitation of
the present invention.
In general in the above discussion the arrays of semiconductor
dies, light emitting elements, optics, and the like have been shown
as square or rectangular arrays; however this is not a limitation
of the present invention and in other embodiments these elements
may be formed in other types of arrays, for example hexagonal,
triangular or any arbitrary array. In some embodiments these
elements may be grouped into different types of arrays on a single
substrate.
The terms and expressions employed herein are used as terms and
expressions of description and not of limitation, and there is no
intention, in the use of such terms and expressions, of excluding
any equivalents of the features shown and described or portions
thereof. In addition, having described certain embodiments of the
invention, it will be apparent to those of ordinary skill in the
art that other embodiments incorporating the concepts disclosed
herein may be used without departing from the spirit and scope of
the invention. Accordingly, the described embodiments are to be
considered in all respects as only illustrative and not
restrictive.
* * * * *